[Truncated abstract] In this thesis I investigated the ingestive and digestive morphology and digestive physiology during development of phyllosomata of the ornate spiny lobster, Panulirus ornatus. This knowledge was applied to develop a suitable formulated diet to be fed in combination with Artemia or used as a supplement to reduce production costs. The major impediment to closure of the life cycle of spiny lobsters has been an inadequate dietary regime, stemming from a lack of information on their feeding biology and ingestive and digestive capabilities. Of all spiny lobster species, P. ornatus is the best candidate for aquaculture in Australia having the shortest larval development phase (46 months) and fast growth rate, attaining 1 kg within 2 years of hatch. Currently, Artemia and fresh feeds such as mussel are used routinely as hatchery feeds. However, the development of a formulated diet that is palatable and delivers the correct balance of nutrients is seen as a highly attractive and cost effective alternative. An appropriate formulated diet for aquaculture of phyllosomata of spiny lobsters can be developed more effectively when the ingestive and digestive morphology, physiology and feeding behaviour are fully understood. ... Partial replacement trials revealed that P. ornatus phyllosoma are stimulated to feed by visual cues. Furthermore, 75% of the entire Artemia ration can be replaced with a formulated diet without having any adverse effects on survival and growth of early-stage phyllosomata. Weaning P. ornatus phyllosomata onto 100% formulated diet during stages II-III resulted in reduced survival but demonstrated that diets containing 44-50% crude protein with a diverse range of marine protein sources provides optimum survival and growth. This thesis has identified both physical and nutritional components that will contribute to the successful development of formulated diets for aquaculture of this species. Ultimately, although formulated diets are ingested and provide more than adequate survival when fed in combination with Artemia during early ontogeny, greater success and the possibility of totally replacing Artemia may occur after day 32 (stage IV) due to an increased efficiency to capture and manipulate larger sized particles externally and a greater capacity to triturate prey and sort and filter particles internally. Furthermore, a general increase in specific activity of digestive enzymes at stage IV suggests the possibility of a greater capacity to digest and assimilate nutrients.

Identifying the extent to which coral reef species are connected by dispersal is a fundamental challenge for developing marine conservation strategies. Many coral reef species are relatively sedentary as adults, yet have a pelagic larval phase where larvae can potentially be widely dispersed by ocean currents. This thesis focuses on the role of ocean currents in driving spatially explicit patterns of population connectivity among ecologically and commercially important coral reef species by combining research tools from population genetics, oceanography, and biophysical modeling. Despite the substantial differences among the life histories of each coral reef species in this thesis, some similarities in connectivity patterns were found among all species. The results of the kinship and genetic outlier analyses consistently found high levels of connectivity among distant populations separated by hundreds to thousands of kilometers. Despite the high levels of connectivity among distant populations, there was substantial variation in gene flow among the populations of each species. The findings of this thesis highlight the importance of international cooperation for the sustainable management of ecologically and commercially important coral reef species in the Caribbean. In conclusion, the findings of this thesis suggest that marine conservation strategies should conservatively plan for uncertainty, particularly since the many of ecological and physical drivers of connectivity among coral reef species in the Caribbean remain uncertain.

Made available in DSpace on 2014-12-17T15:55:02Z (GMT). No. of bitstreams: 1 FranckerDC_DISSERT.pdf: 2209665 bytes, checksum: a3ee455bec642c082742d68093730d12 (MD5) Previous issue date: 2013-02-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / As sociedades humanas sempre se utilizaram dos recursos naturais marinhos como aporte seguro para diversas finalidades, dentre elas, a aquisi??o de alimentos e a gera??o de renda para garantir sua sobreviv?ncia e reprodu??o social. Na conjuntura atual, a pesca artesanal de lagostas espinhosas das esp?cies Panulirus argus (lagosta-vermelha) e Panulirus laevicauda (lagosta-verde) representa uma das principais atividades econ?micas do estado Rio Grande do Norte, constituindo-se na principal fonte de renda de muitas comunidades pesqueiras. No estado, o munic?pio de Touros desponta como o segundo maior produtor do crust?ceo. Contudo, a introdu??o de instrumentos e de t?cnicas predat?rias de pesca, aliada a ado??o da mentalidade capitalista, veem causando transforma??es que se repercutem diretamente na socioeconomia e no meio ambiente dessas comunidades, a exemplo da sobrepesca dos estoques pesqueiros. Assim, o presente estudo possui como objetivo principal analisar a pesca artesanal de lagosta no munic?pio de Touros/RN, considerando os efeitos e as transforma??es decorrentes do uso das t?cnicas de captura sobre a socioeconomia e o meio ambiente. Como objetivos espec?ficos buscaram-se: caracterizar socioeconomicamente a pesca e os pescadores artesanais de lagosta da ?rea em estudo; identificar as pr?ticas e t?cnicas mais utilizadas para a pesca de lagosta correlacionando-as com a sobrepesca e as transforma??es socioecon?micas; determinar os fatores ou mecanismos que vem impulsionando os pescadores artesanais a utilizarem t?cnicas predat?rias na pesca de lagosta, bem como seus efeitos sobre o meio ambiente; identificar as formas de adapta??o dos pescadores artesanais quanto ?s novas condi??es ambientais e socioecon?micas. Para tanto, fez-se uso da pesquisa bibliogr?fica, da observa??o de campo, do registro fotogr?fico, da aplica??o de 86 entrevistas estruturadas e da an?lise de conte?do. Os resultados apontam que os pescadores de lagostas s?o homens de idade avan?ada, casados, com baixo grau de escolaridade e de rendimento financeiro, bem como demonstram o car?ter inst?vel e predat?rio dessa modalidade de pesca. Verificou-se tamb?m que a marginaliza??o social dos pescadores, aliada ?s dificuldades de sobreviv?ncia impostas pelo capitalismo e a ineficiente fiscaliza??o governamental, constituem os fatores preponderantes para o uso das t?cnicas ilegais apontadas. Al?m disso, os resultados mostram que as adapta??es ?s novas condi??es ambientais podem ser positivas no que tange ao aumento da renda e negativas no que se refere ao meio ambiente. Logo, para mitigar os problemas sociais e ambientais ? necess?rio que o Estado priorize o desenvolvimento de pol?ticas direcionadas aos pescadores e a pesca que abarquem tanto as dimens?es de assist?ncia financeira e profissional, quanto uma maior rigidez no que concerne ao sistema de fiscaliza??o e gerenciamento

The time-honored profession of commercial fishing in the Florida Keys is in danger of extinction as each year passes and fewer commercial fishermen remain in an industry that is sinking in the wake of politicians, land developers, and financial woes. At the heart of the problem is the threat of overfishing, a subject that is increasingly at the forefront of media attention and environmental campaigns. The villain in this story of death and destruction more often than not are commercial fishermen. But the blame is misguided. Our fishermen work according to the letter of the law and strive to maintain healthy sustainable fish stocks and sound marine ecosystems. It is unlikely that the American hunger for seafood will diminish so in the absence of locally caught fish the public has no choice but to support the efforts of unchecked foreign fisheries—Fisheries that are not managed as well as ours and in some instances fish until there is nothing left to take. / text

Chemical senses play a critical role in predator-prey and social interactions of many animals. Predators often evoke adaptive escape responses by prey, one of which is the release of chemicals that induce adaptive avoidance behaviors from both predators and conspecifics. I explore the use of chemicals in predator-prey and social interactions, using a crustacean model system, the spiny lobster. As predators, spiny lobsters are opportunistic, polyphagous feeders, and they rely heavily on their chemical senses during feeding. Some of their potential prey deter attacks through chemical defenses that act through the spiny lobsters’ chemical senses. An example of this is sea hares, Aplysia californica, which secrete an ink when vigorously attacked by sympatric spiny lobsters, Panulirus interruptus. I show that that this ink defends sea hares from spiny lobsters through several mechanisms that include phagomimicry, sensory disruption, and deterrence, and that the ink’s efficacy is enhanced by its naturally high acidity. As prey, spiny lobsters rely heavily on their chemical senses to assess risk from predators. One way to assess risk of predation is through ‘alarm cues’, which are injury-related chemicals. I show that injured Caribbean spiny lobsters, Panulirus argus, release alarm cues in their hemolymph, and that nearby conspecifics detect these cues using olfaction. Hemolymph from conspecifics induces primarily alarm behavior in the form of retreat, sheltering, and suppression of appetitive responses. In contrast, hemolymph from heterospecifics, depending on phylogenetic relatedness, induces either mixed alarm and appetitive behaviors or primarily appetitive behaviors. Spiny lobsters also use chemical cues to assess risk during social interactions with conspecific. I show that spiny lobsters use urine-borne chemical signals and agonistic behaviors to communicate social status and that these chemical signals are detected exclusively by the olfactory pathway. Dominant animals increase urine release during social interactions, whereas subordinates do not. Experimental prevention of urine release during interactions causes an increase in agonism, but this increase is abolished when urine of dominants is reintroduced. My findings lay the foundation for neuroethological studies of risk-assessment systems mediated by intraspecific chemical cues.