Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Oceanography in the Faculty of Applied Sciences at the Cape Peninsula University of Technology 2014 / The Tristan lobster Jasus tristani is distributed among several isolated islands and submerged seamounts in the South East Atlantic Ocean. This species occurs only at the Tristan da Cunha group, a British Overseas Territory and the World’s most remote inhabited island, and in international waters at Vema Seamount 1680 km ENE of Tristan. All these populations are exploited commercially. The catch, processing and export of J. tristani is the most important economic activity for the inhabitants of Tristan da Cunha, providing the livelihood of many families and accounting for approximately 80% of the Island’s revenue. Sustainable harvesting of this valuable resource requires accurate long-term data on catch and effort, as well as information on the most important biological parameters such as growth, recruitment, moulting and reproductive cycles. This information is critical for robust assessments and management strategies. This thesis describes the history of the lobster fishery at the Tristan da Cunha island group, reporting on catches and trends in Catch Per Unit Effort between 1967 and 2010. A total of 247,014 lobster samples, both sexes combined, was sampled for size composition and sex ratios, as well as 1,526 lobsters for length/weight relationships, between 1997 and 2010. This confirms earlier findings that females have broader and heavier tails than males for the same carapace length (CL). Results show that males dominate catches at all islands, and their average size was larger than that of females (83.5 ± 14.46 versus 73.4 ± 8.64 mm CL, respectively). Inter-island differences in lobster population structure appear to be caused by differences of food availability as well as in density-dependent growth and survival of young lobsters. The largest lobsters were found at Gough Island (87.2 ± 15.13 mm CL), and the smallest at Inaccessible island (73.2 ± 11.39 mm). Tristan was the next largest to Gough Island (84.0 ± 12.56 mm) followed by Nightingale island (78.2 ± 11.33 mm). Lobsters caught inshore were larger than those caught offshore, although this may be related in part to differences in catches between fishing gear types. This study showed that fecundity increases in a linear manner with CL, and although larger lobsters clearly produce more eggs than smaller ones, the gain in fecundity is not as great as in some lobster species where fecundity is more closely associated with weight. The study showed no significant differences in egg size between islands, or between large and small females at one island. The egg production per gram of body weight and mean egg diameter both seem to be less than reported in an earlier study in the 1990s. While it seems likely that this is due to differences in the way in which samples were collected (with only stage 2 ova collected and measured in this study), the possibility of a decline in fecundity needs to be investigated further. A range of management measures have been developed over the history of the fishery, and important current measures include an annual total allowable catch (TAC) for each island, minimum size limits, and a closed season timed to protect egg-bearing females. The fishery has recently been awarded certification by the Marine Stewardship Council. The study has confirmed that current conversion factors are broadly correct and that different size limits established for each island are justified. Concern is raised, however, by the fall in catch per unit effort and the mean size of lobsters at the three northern islands over the past 7 years. These trends will need to be closely monitored. There are still many uncertainties over key parameters such as growth and recruitment and the intention is to increase the knowledge base and our understanding of the dynamics of the lobster stock. A research plan has been developed, so that progress can be monitored through the gradual implementation of scientifically defendable fisheries management procedures and increased research and monitoring capacity.

Les érymides sont des crustacés décapodes marins ayant une morphologie comparable à celle des homards actuels. Ils sont regroupés au sein d’une unique famille, les Erymidae Van Straelen, 1925, caractérisée par la présence d’une plaque intercalaire dorsale. Ces crustacés sont présents dès la fin du Permien. Ils se sont diversifiés et répandus dans le monde entier au Jurassique et ont perduré jusqu’au Paléocène. Ils sont particulièrement abondants au Jurassique, fossilisés dans des dépôts issus d’environnements variés : de faible profondeur – comme les calcaires lithographiques de Solnhofen (Allemagne) –, très profonds – comme La Voulte (France) –, ou encore dans différents milieux de plate-forme – comme le Terrain à Chailles (France). Depuis les premières descriptions d’érymides, au début du XIXe siècle, de nombreux auteurs se sont attachés à décrire de nouvelles formes et à tenter d’élucider les affinités phylogénétiques de ces crustacés éteints. Ces nombreux travaux ont abouti à l’installation et à la propagation de confusions rendant douteuse la systématique des érymides tant au niveau des genres que des espèces. Ces problèmes taxinomiques particulièrement marqués chez les érymides — on parle d’ailleurs de « problème érymidien » — sont accompagnés d’un débat sur leur classification au sein des Pleocyemata. Jusqu’au début du XXIe siècle, la majorité des auteurs les classaient dans l’infraordre des Astacidea mais de récentes analyses phylogénétiques suggèrent l’intégration des érymides au sein des Glypheidea. Une autre étude a même abouti à la remise en cause du statut éteint des érymides. En effet, Schram & Dixon (2004) ont observé la plaque intercalaire sur l’actuel Enoplometopus A. Milne Edwards, 1862. Leur analyse a ensuite conduit au regroupement de cette forme actuelle avec les érymides au sein d’un même clade nommé Erymida. Les objectifs de cette thèse sont donc de remédier aux problèmes taxinomiques des érymides, d’élucider leurs affinités phylogénétiques et d’apporter des éléments permettant de mieux comprendre leur mode de vie et leur succès évolutif. Pour ce faire, une révision systématique aussi exhaustive que possible, appuyée sur l’étude de plus d’un millier de spécimens, a été réalisée. Elle a permis d’homogénéiser la description des 6 genres et des 75 espèces reconnues et d’identifier les caractères nécessaires à l’étude phylogénétique. L’arbre obtenu montre clairement que les érymides constituent un groupe particulier d’Astacidea auquel Enoplometopus n’appartient pas. De plus, la topologie de l’arbre de strict consensus soutient une refondation complète de la systématique du groupe. D’une unique famille, les érymides se retrouvent désormais répartis dans deux familles, distinguées par la présence/absence de la zone post-orbitaire : les Enoploclytidae n. fam. et les Erymidae. Cette dernière est d’ailleurs elle-même divisée en sous-familles, Eryminae Van Straelen, 1925 et Tethysastacinae n. s.–fam., en raison de l’architecture très simple des sillons de la carapace de Tethysastacus Devillez et al., 2016 comparée à celle des autres genres. Cette étude a aussi été l’occasion de formuler des hypothèses paléobiogéographiques qui demeurent, hélas, en grande partie spéculatives et incomplètes du fait des importantes discontinuités géographiques et stratigraphiques du registre fossile. Les observations de stades larvaires, des yeux, de la morphologie des pinces, de pores cuticulaires et de la variabilité intraspécifique chez certains spécimens ont également permis, en s’appuyant sur les formes actuelles, d’émettre des hypothèses sur le mode de vie de ces crustacés disparus. Enfin, la grande tolérance environnementale déduite des différentes formations géologiques ayant livré des érymides fossiles est probablement une des clés de leur succès au Mésozoïque et soulève la question des raisons de leur extinction. / Erymids are marine decapod crustaceans with a morphology close to that of extant lobsters. They are grouped within an unique family, Erymidae Van Straelen, 1925, based on the presence of a characteristic intercalated plate. These crustaceans were already present in the Permian, have become diversified and widespread during the Jurassic and have lasted until the Paleocene. The erymids are abundant during the Jurassic. They fossilized in deposits from various paleoenvironments: shallow water environments – like lithographic limestones from Solnhofen (Germany) –, from deep environments – like in La Voulte (France) –, and also from different platform environments – like the Terrain à Chailles (France). Since the first descriptions of erymids in the first part of the XIXth century, numerous authors have described new species and have attempted to establish the phylogenetic affinities of these extinct crustaceans. This high number of studies resulted with the apparition and propagation of confusions. So, the systematics of the erymids has become doubtful at both generic and specific levels. These taxonomic problems strongly affecting the erymids — the so called « erymidian problem » — are increased by their uncertain phylogenetic relationships among the Pleocyemata. Until the XXIst century, most of the authors classified the erymids within the infraorder Astacidea but recent phylogenetic analyses suggest an integration within Glypheidea. Moreover, a study has led to question the extinct status of the erymids. Indeed, Schram & Dixon (2004) have observed an intercalated plate in the extant Enoplometopus A. Milne Edwards, 1862. Their analysis has resulted with the clustering of this extant lobster together with the erymids within a same clade named Erymida. So, the purposes of this thesis are to rectify the taxonomic problems of the erymids, to elucidate their phylogenetic affinities and to provide observations which enable a better comprehension of their lifestyles and their evolutionary success. To reach these goals, a systematic review, supported by the examination of more than a thousand specimens, has been done. It has resulted in a homogenisation of the descriptions of the 6 genera and 75 species herein recognized and in the identification of useful characters for the phylogenetic study. The phylogenetic tree obtained clearly shows that erymids form a particular group of Astacidea and that Enoplometopus does not belong to this group. Moreover, the topology of the strict consensus tree supports a new systematic building of the group. From a unique family, the erymids are now spread into two families supported by the absence/presence of a post-orbital area: Enoploclytidae n. fam. and Erymidae. The last is also divided in subfamilies, Eryminae Van Straelen, 1925 and Tethysastacinae n. s.-fam., based on the very simple carapace groove pattern of Tethysastacus Devillez et al., 2016. This new study on the erymids was also an occasion to provide some paleobiogeographic hypotheses. But, unfortunately, they remain speculative and incomplete due to geographic and stratigraphic discontinuities of the fossil record. Observations of larval stages, of eyes, of P1 chela morphologies, of cuticular pores, and of intraspecific variability on some specimens have also enabled comparisons with extant forms. These observations led to provide hypotheses on the lifestyle of these extinct lobsters. Finally, the strong environmental tolerance was probably one of the keys of the success of the erymids during the Mesozoic but raised interrogations about the reasons of their extinction.

nÃo hà / A pesca indiscriminada de lagostas vem causando a diminuiÃÃo dos estoques, minimizando a efetividade da pesca artesanal e reduzindo a renda de comunidades pesqueiras, estimulando a ainda mais a sobrepesca e a captura de indivÃduos juvenis. Como alternativa, vem sendo implantadas as marambaias, que sÃo estruturas para fixaÃÃo de microorganismos aquÃticos para a formaÃÃo de cadeia trÃfica, servindo como atrator para espÃcies de interesse comercial. Na praia de Ponta Grossa, IcapuÃ- CE, o uso de marambaias voltadas prioritariamente para a pesca de lagosta partiu de pescadores locais em 2002. Com o sucesso das primeiras pescarias, houve âbloomâ de marambaias instaladas e dificuldade de controle sobre o uso das mesmas. Sobre o litoral cearense ainda sÃo poucas as informaÃÃes sobre o efeito de marambaias para a atraÃÃo de lagostas. Visando dar subsÃdios ao ordenamento de uso dessas estruturas, urge a necessidade de se determinar a efetividade para o aumento da produtividade e avaliar os impactos socioeconÃmicos e ambientais. Marambaias para lagosta sÃo estruturas de madeira com 30 cm de altura da base e 6 m2 de Ãrea. O lanÃamento foi realizado pelos pescadores em profundidades entre 3 e 13 m. Participaram deste estudo 36 pescadores. Foram analisados dados de 484 pescarias nos anos de 2003 (Ano I) a 2005 (Ano III), sendo 280 em profundidades <5 m e 204 em profundidades >5 m. A escolha dos intervalos de profundidade foi arbitrÃria. Estes dados serviram para a determinaÃÃo da captura por unidade de esforÃo (CPUE), do tamanho mÃdio das lagostas e do percentual de lagostas com tamanho comercial. A avaliaÃÃo socioeconÃmica foi realizada pelo cÃlculo do rendimento das pescarias. A avaliaÃÃo do impacto ambiental foi realizada pelo mÃtodo G.U.T.. O comprimento mÃdio das lagostas (Panulirus argus) ficou abaixo do tamanho mÃnimo determinado por lei (13 cm). As CPUEÂs ficaram acima da mÃdia histÃrica do CearÃ, indicando a eficiÃncia destas estruturas para o aumento da produtividade, embora os valores de receita mÃdia por pescador tenham sofrido significativa queda na renda no segundo e terceiro anos, indicando que houve apenas concentraÃÃo do estoque nas pescarias no primeiro ano. No Ano I, os impactos negativos mais significantes foram a sobreexploraÃÃo do estoque e a incidÃncia de lagostas juvenis nas capturas. Os impactos positivos mais significantes foram o incremento da pesca local, a criaÃÃo de novos habitats, o desenvolvimento de tecnologias e o fomento a pesquisa cientÃfica. No Ano III, os impactos negativos mais significantes foram a incidÃncia de lagostas juvenis nas capturas, a reduÃÃo da biomassa de pescado, a sobreexploraÃÃo de estoques pesqueiros e a reduÃÃo da pesca local. Quanto aos impactos positivos, destacam-se a reduÃÃo das pescarias com rede de emalhar e o fomento a pesquisa cientÃfica. Concluise que as marambaias nÃo atuaram de forma sustentÃvel, pois funcionaram apenas como concentradoras de estoque. Recomenda-se que o uso de marambaias deve obedecer a um plano de manejo e respeitar as normativas de proibiÃÃo da captura de juvenis de lagosta. / The indiscriminate lobster fisheries has been causing stock reduction, minimizing the effectiveness of artesian fisheries and reducing the income of fishing communities, stimulating even more the overfisheries and the capture of undersized lobsters. As an alternative, the community has been implanting artificial reefs, which are structures where microorganisms settle forming a feeding chain, therefore serving as an attractor for commercial species. At Ponta Grossa community, Icapuà â CE, the use of artificial reefs exclusively for lobster fishing was an initiative taken by some of the local fishermen in 2002. With the successful result of the first fisheries at the artificial reefs, a fast increase on the number of artificial occurred, what made the control of their use very difficult. So far, there a very few information about the effects of artificial reefs on the lobster fishery at Cearà State. In order to provide information to organize the use of these structures there is an urgent need to determine the real effectiveness of the initiative in terms of increasing fisheries and to evaluate social, economic and environmental impacts. The artificial reefs for lobster are build of wood measuring 30 cm in height and 6 m2 of Ãrea. The launching of the structures was carried through by the fishing in depths between 3 and 13 m. A total of 36 fishermen took part in this study. Data from 484 fishing activities were analyzed during the years of 2003 (year I) to 2005 (year III), being 280 of them in shallow waters (less than 5 m of depth) and 204 in waters deeper than 5m. These depths intervals were chosen arbitrarily. The data were used to determine the amount of lobster captured in relation to the fishery effort (CPUE), the average lobsterâs size and the percentage of lobsters above the legal commercial size. The socio-economic analysis was performed using the profit earned by each fishing activity. The environmental impact was performed by G.U.T. method. The results showed that the average size of captured lobsters (Panulirus argus) was below legal minimum size (13 cm). The amount of lobster captured in relation to the fishery effort was above the historical average of Cearà State, showing the efficiency of these structures to increase productivity, however the values for the average profit per fisherman decreased significantly during the second and third years of the study, suggesting that in the first year occurred just a concentration of lobster stock in the same area. In the first year the most significant negative impacts were the over exploitation of the stocks and the occurrence of juvenile lobster on the catches. The most significant positive impacts were the increase of local fishery, the formation of new habitats, the development of new technologies and the possibility to develop scientific research. In Year III the most significant negative impacts were the presence of juvenile lobsters in the catches, the reduction of fisheries biomass, the over exploitation and the reduction on the amount of local fishery. In relation to positive impacts, the reduction of the fisheries using gill nets and the possibility for scientific research were the most evident. In conclusion, the artificial reefs have not played a sustainable role because the main result was just the concentration of stocks in the same area. The use of artificial reefs should follow a management plan and respect the law restriction on capturing juvenile lobsters.

The western rock lobster (WRL), Panulirus cygnus is a decapod crustacean which is found in abundance in the coastal waters of Western Australia and which supports a major fishery of economic importance for the State, with an annual harvest ranging between 10-12 million kilograms. The growth of the existing markets in Asia for live exports and the competition exerted by other countries marketing spiny lobsters prompted the need for the Industry to assess and develop post-harvest handling procedures likely to contribute to an improved quality of live product. The physiological responses of P. cygnus to handling and transportation were virtually unexplored.The objectives of this project were, (i) to generate information with regard to the biological phenomena underlying morbidity and mortality of lobsters during live export shipments, (ii) to investigate the physiological responses of P. cygnus to the post-harvest handling practices currently used by the WRL industry in their five export program and, (iii) to identify protocols by which post-harvest handling techniques could be modified to reduce the occurrence of morbidity and mortality during five export.These objectives were achieved through, (i) a field survey conducted during the course of the 1992/93 fishing season, investigating the relative influence of environmental factors and processing techniques on the incidence of lobster morbidity+mortality during simulated live shipments and, (ii) a series of field experiments that monitored the physiological responses elicited by lobsters to post-harvest handling procedures and simulated live shipment conditions.From the field survey, it appeared that the rate of morbidity+mortality experienced in simulated live shipments, within the three processing units surveyed, averaged 5.22 +/- 0.63 %, with a highly significant difference (p [less than] 0.001) between the ++ / processing units. Scrutiny of the data revealed a major influence of two factors directly related to post-harvest handling procedures: a) the time spent under normal commercial conditions in packaging export cartons and, b) the ambient temperature within the export cartons. Following 30-36 hrs in packaging, the percent mortality increased twofold, from 5.2 +/- 0.0 % recorded following 20 - 24 hrs to 10.4 +/- 2.3%. With regard to the ambient temperature within the export carton, temperatures between 17.5 and 20.0 degrees celsius appear to be optimal for P. cygnus survival while temperatures above 20.0 degrees celsius induce significantly greater morbidity and mortality.A number of factors were identified as having a potential influence on lobster physiological responses to post-harvest handling conditions:a)Immediately after harvesting, lobsters are subjected to a range of transport environment options, according to their origins: i.e., (i) direct delivery from fishing vessels by local fishermen to the processing facility, (ii) onshore transportation by truck from coastal depots and, (iii) transport in baskets on board carrier-boats from the Houtman Abrolhos Islands.b) After delivery, lobsters are subjected to sorting and grading procedures, with a concomitant exposure to air and disturbance.c) Recovery in holding tanks is usually allowed for a period ranging between 24 to 72 hours.d) Prior to being packed in export cartons, lobsters are subjected to a short period (30 sec to 3 min) of immersion in chilled water (8 - 12 degrees celsius), the procedure varying from one processor to the other.e) During subsequent periods of transit in export cartons, (up to 48 hrs) lobsters are subjected to aerial exposure and fluctuating ambient temperature.A comparison of the physiological profiles of lobsters from different origins revealed significant differences, with respect to a ++ / range of physiological variables. On the basis of visual estimates of health status, lobsters from the "local" origin exhibited a consistently superior condition, when compared to "coastal" and "carrier-boat" animals. The examination of physiological variables revealed consistent trends reflecting the visual assessments. "Local" lobsters exhibited significantly lower levels in anaerobic metabolic waste concentrations, with the haemolymph lactate titre between 2.77 +/- 0.19 and 4.33 +/- 0.56 mmol L(subscript)-1, compared with the other groups, between 5.23 +/- 0.24 and 8.86 +/- 1.29 mmol L(subscript)-1. A 250 to 300% increase in haemolymph ammonia concentration was observed between "coastal" and "carrier-boat" groups and the "local" lobsters, at 0.32 +/- 0.02 mmol L(subscript)-1. Significantly higher pH values were recorded for the "local" group, at 7.72 +/- 0.04, compared with values below 7.64 +/- 0.04 for the other groups. "Local" lobsters recorded 8 to 15 times less circulating glucose, at 0.11 +/- 0.03 mmol L(subscript)-1, having 50% more ATP in their muscle tissues, at 6.07 +/- 0.15 mu mol g(subscript)-1 and 250% more arginine phosphate, at 6.56 +/- 0.72 mu mol g(subscript)-1.An assessment of the efficiency of the industry sorting procedures revealed differences between selected and rejected animals with regard to the ATP and arginine phosphate concentrations in their muscle tissues with, as a common trend for both variables, selected animals recorded higher values. Significant differences were identified within the "local" group of lobsters, with selected animals recording 40% more ATP, at 6.92 +/- 0.63 mu mol g(subscript)-1 and 30 % more arginine phosphate, at 7.77 +/- 1.01 mu mol g(subscript)-1.A monitoring of the physiological profiles of lobsters subjected to extended (up to 8 hours) periods of onshore transportation in trucks revealed a significant ++ / reduction in their health status. A consistent and almost linear fall in the concentration of total adenylate (35%), to 5.46 +/- 0.50 mu mol g(subscript)-1 and phosphagen reserve (70%),to 2.77 +/- 0.26 mu mol g(subscript)-1, were recorded throughout the 8 hour period. For up to 6 hours the concentration of lactate in the leg muscle tissues increased by 0.95 mu mol g(subscript)-1 h(subscript)-1 and then by 4.7 mu mol g(subscript)-1 h(subscript)-1,to reach 20.57 +/- 1.61 mu mol g(subscript)-1 after 8 hours. Haemolymph glucose and ammonia titres recorded a 3.5 fold increase over the first 6 hours, to reach 2.14 +/- 0.54 and 1.17 +/- 0.16 mmol L(subscript)-1, respectively, the last period (6 to 8 hours) being characterised by a 1.6 and 1.9 fold decrease in concentration. Lobsters were able to maintain their haemolymph pH close to 7.77 during the first four hours, with a concomitant rise in haemolymph calcium concentration. From the results, it appeared that, under current industry procedures, extending the period during which lobsters are transported in spray trucks to more than 6 hours is conducive of altered physiological status.An assessment of the effects of short periods (up to 60 min) of aerial exposure and disturbance revealed significant changes in the physiological profiles of lobsters. When exposed to air, lobsters exhibited a significant fall in haemolymph pH, a rise in lactate concentration, and a depletion in energy reserves. Lobsters left undisturbed were able to buffer an incipient acidosis for up to 40 min (7.78 +/- 0.03), after which a decline in pH was recorded to reach 7.71 +/- 0.02. Conversely, disturbed animals experienced an uncompensated acidosis and a decrease by 0.7 of a unit over a 60 minute period. Similarly, undisturbed lobsters did not demonstrate behavioural signs of stress while disturbed animals exhibited dramatically diminished responses ++ / to handling after 60 min of exposure. Both disturbed and undisturbed animals recorded a decline in ATP/ADP, to reach after 40 min, 8.31 +/- 0.77 and 5.05 +/- 0.45, respectively, compared to 13.18 +/- 1.69 (control). During the last period (40 to 60 min), the undisturbed animals recorded a 40 % decrease in ATP concentration, to reach 4.42 +/- 0.16 mu mol g(subscript)-1, while a 53% decline was recorded in the disturbed group, to 3.59 +/- 0.41 mu mol g(subscript)-1. During aerial exposure, the phosphagen reserve recorded a 55% decrease in the disturbed animals, at 4.82 +/- 1.37 mu mol g(subscript)-1, compared to 20% in the undisturbed group, at 8.64 +/- 0.87 mu mol g(subscript)-1. A 100% increase in lactate ion concentration was recorded in the muscle tissues of disturbed animals to reach 5.53 +/- 0.49 mu mol g(subscript)-1, compared to a 15% increase in the undisturbed group, at 2.83 +/- 0.29 mu mol g(subscript)-1.The monitoring of the physiological profiles of lobsters during extended periods (up to 72 hrs) of recovery in holding tanks revealed significant shifts in their physiological profiles and that a return to a steady state occurred only after 8 to 48 hours following re-immersion, according to the environmental conditions and the origin of the animals. Resting levels were identified after 24 hours for the haemolymph pH (close to 8.00), for the concentration in lactate, ions in the muscle tissues (2.00 to 3.00 mu mol g(subscript)-1 for the haemolymph glucose titre (0.30 to 0.60 mmol L(subscript)-1), for the haemolymph ammonia titre (close to 0.25 mmol L(subscript)-1), for ATP (6.50 to 7.70 mu mol g(subscript)-1), and for the phosphagen reserve (12.2 to 16.70 mu mol g(subscript)-1). Longer periods ([greater than]/= 48 hrs) were required for full recovery to occur when lobsters were stored at high stocking density and when lobsters were not isolated from their ++ / artificial environment. Extending the recovery period to 72 hrs resulted in slight changes in the physiological profiles of lobsters, with a 20 % decline in ATP/ADP, a 10% decrease in phosphagen concentration in the muscle tissues of the lobsters and subdued behavioural responses for those lobsters held at higher stocking densities.No attempt was made in the present study to establish the resting levels for the physiological variables surveyed. In a number of experiments, "control" groups have been studied and used as reference points to monitor changes accompanying exposure to a range of environmental conditions. The data pertaining to these different groups revealed a variability for most of the variables surveyed, suggesting that it would be hazardous to assume that these animals were undisturbed and to state with confidence that the values recorded for the variables surveyed would represent resting levels.The physiological responses of lobsters subjected to chilling procedures was investigated and significant physiological changes were identified. Short chilling procedures (3 and 6 min) were conducive of a dramatic reduction of the behavioural responses to handling, a reduction in pH values ranging between 0.13 and 0.24 of a unit, a rise in haemolymph lactate concentration by 1 to 2.6 mmol L(subscript)-1, a 20 to 100% increase in haemolymph glucose titre, a 35 to 75% decrease in phosphagen concentration. Extending the chilling period for up to 24 hrs resulted in a progressive return to control levels for most of the physiological variables surveyed. However, physiological signs of disturbance remained perceptible between 2 to 15 hours, as demonstrated by elevated lactate concentrations, lowered ATP and AP concentrations and lowered ATP/ADP values.Lobster body core temperature (CBT) reduction resulting from immersion in chilled water suggested that limited cooling ++ / effects were achieved by using the standard chilling procedures currently used by the WRL industry. Using "A" size lobsters (395 - 453 gr), a reduction of the CBT by 0.5 to 0.8 degrees celsius was recorded after 1 and 3 min immersion in 12 degrees celsius water, highlighting the limited low temperature effect exerted by these procedures in lowering the overall temperature of the mass of the product to be packed into export cartons.A study of the general physiological responses of lobsters to simulated live transport conditions in export cartons was conducted, investigating the effects of the period spent by the animals in export cartons, the effects of environmental temperature and the impact of chilling regimes. No attempt was made to duplicate exactly the conditions of cartons shipped overseas, that is carted by trucks to the airport and then transported by air to foreign markets. This study revealed that during the first 4 hours of transit, the animals exhibited physiological changes probably related to delayed responses to handling, disturbance and chilling procedures, as demonstrated by a decline in pH (0.1 to 0.3 of a unit), a rise in haemolymph ammonia (0.5 to 1 mmol L(subscript)-1) and glucose (0.5 mmol L(subscript)-1) titres, an increase in muscle lactate concentration (0.5 to 1 mu mol g(subscript)-1, a decrease in ATP concentration (1.5 mu mol g(subscript)-1, and a partial replenishment of the phosphagen reserve. These changes were less pronounced for those lobsters which underwent intermediate (30 min) chilling treatments.The subsequent periods (to 48 hours) were characterised, for all the treatments, by a rise in lactate concentration in the muscle tissues, this response being delayed for those lobsters which underwent a "6 min" or "30 min" chilling treatment. The data suggested that moderate changes in haemolymph lactate titre resulted from the increase ++ / in muscle lactate concentration, up to values ranging between 6 and 8 mu mol g(subscript)-1, beyond which levels, haemolymph lactate rose dramatically, to reach values up to 19.98 mmol L(subscript)-1. The ATP concentration remained relatively constant up to 18 - 26 hours, after which a steep decline was recorded to reach values below or close to 4 mu mol g(subscript)-1 after 42 hours, suggesting that the adenylate pool was maintained, probably through aerobic and anaerobic pathways of energy generation and by the "buffering" role played by the phosphagen reserve. After 24 to 36 hours, all the lobsters exhibited signs of energy depletion, as demonstrated by the changes in ATP/ADP ratio. A concomitant increase in lactate ion concentration and a decrease in haemolymph glucose titre was recorded, suggesting that anaerobic metabolism had become the major component of energy production. Simultaneously, a marked increase in the internal carton temperature was identified, which probably induced an increase in the metabolic rate of the lobsters. This "temperature effect" was delayed for up to 32-38 hrs transit, for those lobsters which underwent intermediate (30 min) and extended (24 hrs) chilling treatments. The changes in haemolymph pH and calcium titre suggest that the initial decline in pH identified at the completion of the first 4 hours of transit was, at least partially, compensated after 26 - 32 hours. A 30 to 40% increase in haemolymph calcium titre was recorded after 4 hours of transit, suggesting that bicarbonate ions were released in order to buffer the pH of the haemolymph. However, a decrease in pH (0.1 to 0.3 of a unit) was recorded during the subsequent periods suggesting that the bicarbonate buffering capacity did not suffice to match the recorded massive rise in lactate titre.By extending the duration of the chilling procedures and by using refrigerated ++ / material (wood-shaving fillers, ice-bottles), lower temperatures were achieved inside the packaging cartons and these were maintained for longer periods of transit (up to 20 hours), delaying the effect of the external environment on the temperature changes recorded inside the cartons and the concomitant metabolic responses of the animals. This effect was also achieved by maintaining the cartons in controlled temperature environments ([less than] 20 degrees celsius) and, to a lesser extent, by improving the insulation capacity of the polystyrene cartons.This study constitutes an overview of the physiological responses of Panulirus cygnus to post-harvest handling procedures currently used by the WRL industry. It revealed that an improved return for the Industry could be achieved by reducing the debilitating effects exerted on the lobsters by handling, exposure to air and elevated environmental temperature. It provides direction for future research, aimed at improving the quality and hence, the financial return in the live export of WRL.

Caribbean spiny lobster (Panulirus argus) is a popular and heavily exploited seafood throughout its range. This species supports the primary fishery in many Caribbean countries, especially in the Bahamas, which reports the highest catches and where spiny lobster serves as the number one food export. P. argus possesses one of the longest pelagic larval durations of any marine species, ranging from 6-12 months. This allows for the possibility of long-range dispersal, which would make it difficult to determine if local adult populations originate from areas close-by or within the same countries/jurisdictions, thus presenting implications for conservation and management of the species. This project seeks to explore the policy implications of lobster larval dispersal in the Bahamas by examining the larval connectivity of locally spawned P. argus in order to determine the mean dispersal kernel and to identify hotspots of settlement within the area. A coupled biophysical model was used to simulate larval transport from scaled egg production of 47 release locations within the Bahamas. The model was initialized bi-weekly from April through May, the highest months of larvae production in the Bahamas, with each model run occurring for a maximum of 180 days. The dispersal kernel for the Bahamas was calculated to be an average of 100-300 km, indicating that the larvae released within its boundaries typically settled there as well. Due to the long pelagic larval duration, larval particles were able to travel extensive distances, averaging trajectories covering distances of 4000 km and greater from the source locations. Yet, those same larval particles still settled in locations within the Bahamas, suggesting local retention, which varies from the common perception that lobster in the Bahamas originate elsewhere. This knowledge can be used to assess and perhaps reevaluate conservation and management strategies related to the Bahamian P. argus fishery, including the implementation of MPAs and/or MPA networks, input and output management controls, and other management tools.

Constantly changing environments force animals to adapt by cycling through multiple physiological states. Plasticity in sensory, motor, and modulatory neural circuits is an essential part of these adaptive processes. Invertebrates with their accessible, identifiable neurons are excellent models for investigating the molecular and cellular mechanisms underlying state-dependent neural plasticity, and provide insight into similar processes in more complex systems. These properties have allowed highly detailed characterization of several crustacean circuits with respect to their connectivities, cellular properties, responses to various inputs, and outputs. Serotonin (5-HT) is an important neuromodulator in virtually every animal species. 5-HT signals are mediated primarily by a large family of metabotropic receptors on target cells that activate diverse intracellular signaling cascades. Although 5-HT’s effects on crustacean circuits have been studied in detail, the mediating receptors have been inaccessible until recently. Crustacean receptors had not been cloned and specific drugs for use in physiological experiments could therefore not be identified. Coupling properties of 5-HT receptor families are strongly conserved between phyla, but pharmacological profiles are not. The extent of pharmacological divergence among invertebrates is unclear, however, as no systematic functional profile of 5-HT receptors from related species has been determined. This work shows that orthologs of two 5-HT receptors, 5-HT2b and 5-HT1a, are highly conserved at the molecular, functional and pharmacological level between two distantly related decapod crustaceans, Panulirus interruptus and Procambarus clarkii. A suite of drugs was functionally characterized at Panulirus and Procambarus 5-HT2b and 5-HT1a receptors in cell culture, which were then used to investigate the roles of the receptors in pyloric cycle frequency modulation in the stomatogastric ganglion, a model central pattern generator. The two receptor subtypes were found to serve different roles in the circuit and their function depends on the initial state of the circuit. Finally, an antibody recognizing 5-HT1a was used to map the localization of this receptor within the crayfish nervous system. 5-HT1a is localized to somata and neuropil throughout the nerve cord, suggesting it may respond to synaptic, paracrine or neurohormonal 5-HT signals. The protein and mRNA expression levels are variable between individual animals, perhaps reflecting distinct physiological states.

Odor signals mediate a variety of behaviors in animals across a diversity of taxa. Despite dramatic morphological differences between animals from different taxa, several important features of olfactory system organization and processing are similar across animals. Because of this similarity, a number of different organisms including mammals, insects, and decapod crustaceans serve as valuable model systems for understanding general principles of olfactory processing. As in other organisms, including both vertebrates and insects, the chemosensory system of decapod crustaceans is organized into multiple anatomically distinct neuronal pathways. The two main pathways (the aesthetasc/ olfactory lobe pathway and non-aesthetasc/ lateral antennular neuropil pathway) originate in different populations of antennular sensilla and project to different neuropils in the brain. The functional significance of this parallel organization is not well understood in crustaceans or in many other species. Although in some insect species the functions of parallel pathways are clearly delineated by the types of odors processed by each, functional differences between parallel pathways in other organisms are much less distinct. A critical step towards understanding the functional significance of the multiple chemosensory pathways is to identify the specific behaviors that are driven by each pathway. Using spiny lobsters and crayfish as model organisms, the importance of each pathway was examined in three different behavioral contexts: (1) orientation to a distant food odor, (2) shelter selection in response to conspecific chemical signals, and (3) determination of conspecific social status. In each study, selective ablations of specific populations of antennular sensilla were performed, and the behavior of ablated animals was compared to that of intact controls. Results show that either the aesthetasc or non-aesthetasc pathway is capable of driving orientation to food odors, suggesting functional redundancy between the pathways in this behavior. In contrast social odors are processed preferentially by the aesthetasc pathway rather than the non-aesthetasc pathway, suggesting a unique role for the aesthetasc pathway in this context. As in other organisms possessing multiple chemosensory pathways, the dual antennular pathways in crustaceans display both unique and overlapping functions depending on the chemicals examined, and the behavioral context in which the signal is presented.

This dissertation investigated larval release and larval behavior of the Caribbean spiny lobster Panulirus argus and the spotted spiny lobster P. guttatus. These species were examined under laboratory conditions to determine the phase relationship between larval release and natural environmental cycles. P. argus displayed a nocturnal tidal rhythm, while P. guttatus displayed a circadian rhythm in larval release. P. argus releases larvae near the time of nocturnal high slack water, while P. guttatus released larvae near the time of sunrise. The role of 'pumping pheromones' in controlling larval release behaviors was tested by measuring the pumping response of ovigerous P. argus to (1) hatch water, (2) homogenized-embryo water, (3) embryo-conditioned water, and (4) water containing homogenized-egg cases. Lobsters with late-stage embryos displayed increased pleopod pumping with increased concentration of hatch water. Water individually conditioned with homogenized late-stage embryos, intact late-stage embryos, and homogenized egg-cases induced pumping activity in females with late-stage embryos, indicating the presence of a chemical cue. I quantified pumping responses upon exposure to synthetic peptides to determine if they mimicked pheromones that induce larval release behaviors. Pumping behavior was evoked by oligopeptides with a basic amino acid at the carboxy-terminus, preceded by several neutral amino acids. Carboxyl-terminal arginine peptides serve as pheromone mimics. I investigated whether these peptides originate from the action of trypsin-like enzymes by conducting a bioassay measuring pumping activity of ovigerous P. argus subjected to increasing concentrations of trypsin, trypsin inhibitor, and a combination of the two. Pumping activity increased with increasing concentrations of trypsin and trypsin inhibitor, while behaviors ceased when ovigerous females were subjected to a complex of the two. Pheromones are generated by trypsin-like enzymes assisting in the degradation of the egg membranes at the time of hatching. Vertical swimming behaviors of stage-I phyllosoma larvae of P. argus and P. guttatus were observed under laboratory conditions. P. argus larvae displayed a pattern of twilight vertical migration, while P. guttatus larvae displayed nocturnal diel vertical migration (DVM). Rhythms persisted for 5-6 cycles under constant conditions, indicating that an endogenous rhythm in activity plays a proximate role in DVM for both species. / Dissertation

The research pursued relates to the establishment of interrelationship between various factors affecting chitin extraction, and combination of optimum levels of factors required to maximize the yield of chitin extraction. Optimization of chitin extraction was carried out using crab, lobster, and shrimp solid wastes. The study was divided into two stages: (a) optimization of chitin extractability with respect to particle size; (b) optimization of demineralization and deproteinization stages in lobster chitin extraction using Response Surface Methodology. Particle size had a significant effect on crab and lobster chitin extractability; a particle size of 2.0mm gave the highest yield in chitin extraction. The mean yield of chitin from crab and lobster at particle size of 2.0mm were 28.8% and 23.2%, respectively. Shrimp chitin extractability was not affected by particle size with the mean yield being 25.2%. Response Surface Methodology was used to determine simultaneous effects of (a) concentration of extractant; (b) shell:extractant ratio; (c) temperature of extraction; and (d) time of extraction on deproteinization and demineralization stages of chitin extraction and hence yield of chitin. All variables had an effect on demineralization and deproteinization yields. Maximum demineralization was predictable by a multi-factor model consisting of a combination of concentration of HCl, shell:extractant ratio, temperature and time of extraction. (Abstract shortened by UMI.)

The scalloped spiny lobster, Panulirus homarus has a subspecies trio that are widely distributed in shallow-water habitats in the South West Indian Ocean. Subspecies are defined by differences in colour and abdominal sculptural pattern. A red variety with the megasculptural carapace pattern, P. h. rubellus is distributed along the south east coast of Africa and Madagascar, where they are endemic. Along the African coast P. h. rubellus stocks traverse political boundaries, Mozambique and South Africa. This project aimed to facilitate regional fisheries management of shared stocks by employing genetic tools to determine whether stocks (or populations) are indeed shared between countries. Lobster samples were collected from seven localities throughout the east African coast. The mitochondrial cyctochrome c oxidase subunit 1 region was sequenced to assess the genetic diversity 1) between different subspecies, P. h. homarus and P. h. rubellus and 2) between populations of P. h. rubellus across its African distribution range. Using DNA barcoding methods, genetic diversity was also found between morphologically distinct subspecies, Panulirus homarus homarus and P. h. rubellus which differed genetically by ca. 2-3% in sequence divergence. Both subspecies were monophyletic relative to the out-group taxa and formed well supported sister clades (BI: 1.00, ML: 93%, P: 100%, NJ: 100%). The distribution of P. h. rubellus along the African coast occurs adjacent to different current regimes and therefore varied larval transport modes (i.e. Agulhas Current and inshore countercurrents along the Eastern Cape). This may have driven the formation of subpopulations (ΦPT = 0.104, p = 0.010) which differ by ca. 1.7% in sequence difference. The pattern of gene flow of populations of P. h. rubellus lends support to the Agulhas Current being a major mode of larval transport as well as corroborates previous abundance and distribution records. Time since population expansion estimates for the P. h. homarus and P. h. rubellus subspecies as well as for the P. h. rubellus subpopulations dated back to the mid-Holocene Epoch in accordance with a warmer, more stable marine environment. Genetically distinct subspecies of P. homarus as well as differentiated subpopulations of P. h. rubellus calls for a re-visit of the current collective management of P. homarus as well as P. h. rubellus as a single genetic stock along the south east African coast. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2013.