Nephrops norvegicus is a deep water marine decapod crustacean which burrows in fine muddy substrata. It is a commercially important as a fisheries species, but knowledge of its biology, particularly concerning its endocrinology, is limited. This thesis describes the endocrinology of Nephrops norvegicus with particular reference to crustacean hyperglycaemic hormone. Histological investigations of the eyestalk of Nephrops norvegicus enabled the identification d" the X-organ sinus gland complex. The development of a microbioassay allowed the determination of increases of glycaemia following the injection of crude sinus gland extracts into a host animal. The optimal dose for induced haemolymph glycaemia was determined. HPLC separation was used to isolate and purify several neuropeptides from crude sinus gland extracts, which had varying degrees of hyperglycaemic activities. The use of ELISA (enzyme linked immunosorbent assay) showed that the peptides reacted with polyclonal rabbit antiserum raised against the CHH of the crayfish Orconectes limosus and with polyclonal guinea pig antiserum raised against the CHH of the lobster, Homarus americanus. SDS-PAGE of these peptides enabled an estimation of their molecular weights and the purity of one of the active peptides was determined using capillary electrophoresis. The effects of photoperiod and severe hypoxia on the CHH-induced hyperglycaemia of Nephrops norvegicus were also investigated. The responses of N. norvegicus appeared to differ in some respects from other decapods species. Pairs of oligonucleotide primers, based on the sequence of the lobster, Homarus americanus, complimentary to regions of the CHH sequence, were used in the polymerase chain reactions (PCR). Complimentary first strand DNA (cDNA) was synthesised from total Nephrops eyestalk RNA. 35 rounds and 40 rounds of PCR amplification produced a l00bp and 230bp double stranded DNA product respectively, which were resolved by electrophoresis on a tris-borate-EDTA gel. The product size was compared with known standards. Finally, the identification of CHH and GIH synthesis and storage in the eggs of Nephrops norvegicus at various stages of development was investigated. By the use of PCR, it was not possible to determine if synthesis of CHH was occurring in 50% developed eggs. The use of ELISA, however, demonstrated that in 90% developed eggs there was a significant increase of both CHH and GIH immunoactivity.

The bilaterally paired commissural ganglia of the lobster, Homarus gammarus, form part of the stomatogastric nervous system. The functional organization of these ganglia has been investigated using a variety of anatomical and physiological techniques. There are no consistent differences between right and left commissural ganglia. Each contains the somata of several hundred interneurons and about sixty motorneurons which supply the labrum and oesophagus. There are many input and output pathways to and from the commissural ganglia, including a large number of sensory fibres. There appears to be much interaction between these ganglia and the central and stomatogastric nervous systems. A comparison of the vitro preparation and previous studies of the semi-intact animal have shown that the isolated commissural ganglion contains at least the minimal pattern generator for oesophageal peristalsis. The isolated ganglion can also produce other rhythms, including a putative labral rhythm. The small size of most commissural ganglion neurons precludes intracellular recording and dye injection. Most "recordable" somata are silent. The activity of several neurons, including labral motorneurons, is closely related to the oesophageal rhythm. At least one neuron exhibits rhythmic activity unrelated to the oesophageal cycle. Other neurons show a tonic firing pattern; their possible functions are discussed. A large dopamine-containing neuron sends a corollary discharge of foregut activity to at least the brain. The structure and function of this neuron is discussed in detail. This study suggests that the commissural ganglia have the integratory potential to act as coordination centres for the foregut. The findings are considered in the context of the operation of the stomatogastric nervous system and suggestions are made for further research.

The dissertation describes the gross neuromuscular anatomy of the labrum (upper lip) and oesophagus of the lobster Homarus gammarue as a pre-requisite for studies on the mechanisms and control of food ingestion. Sense organs of the area are also described. Of particular interest are two paired sensors (the anterior and posterior oesophageal sensors) which are bilaterally situated at the oesophageal/cardiac sac valve. These are similar to contact chemoreceptors previously described in insects, and are classified as such on morphological grounds and with indirect electrophysiological evidence. The labrum undergoes rhythmical retraction/protraction movements during feeding and can be shown to participate in both the mandibular rhythm and oesophageal peristalsis. Its role in feeding is discussed. Subsequently, small labral protractions are used as an indication of the duration and frequency of oesophageal peristalsis. Oesophageal peristalsis is effected by the co-ordinated contraction of the oesophageal musculature. This is controlled by rhythmical bursting neuronal activity which can be recorded from the nerve trunks in the area, A characteristic burst recorded from the superior oesophageal nerve is used as an indication of oesophageal dilatation during peristalsis for studies on the feedback effects of the oesophageal sensors. Electrical and chemical stimulation of the posterior oesophageal sensors can initiate and increase the frequency of oesophageal peristalsis, while stimulation of the anterior oesophageal sensors can slow and terminate oesophageal peristalsis. The results are discussed and, in conclusion, a model of the role of the oesophageal sensors in feeding is presented.

The defence reactions of the shore crab, Carcinus maenas, to a range of viruses were investigated in vivo and in vitro. In vivo studies with injected bacteriophages showed that C. maenas is capable of discriminating between different bacteriophages and actively removes certain phages from the haemocoele. Rapid initial clearance of the coliphage T2 was followed by slower removal and the phage persisted in the circulation for at least two weeks. The phage was sequestered to the hepatopancreas where it persisted for at least 72 h. Haemocyte counts remained unchanged upon injection of T2. With respect to prophenoloxidase activation, of the viruses tested only the Chlorella phage PBCV-1 was found to activate haemolymph prophenoloxidase at concentrations above 107 particles ml-1This indicates that C. maenas may respond to high concentrations of viruses in vitro. However, neutralization assays failed to reveal inactivation of viruses in HLS, plasma, or extracts of the hepatopancreas, gut, gill or heart, although some activity against an insect baculovirus and parainfluenza vims was detected in digestive juice. At least four antibacterial proteins, of ca. 6.5 kDa, 11.6 kDa, 20 kDa or 25 kDa, are present in C. maenas haemocytes. One, a 6.5 kDa peptide with activity against Gram positive and Gram negative bacteria, was purified. The N-terminal 30 amino acids of this peptide share over 60% sequence identity with bovine Bac 7, a mammalian cathelicidin. This 6.5 kDa peptide in C. maenas is the first antimicrobial peptide described from the Crustacea. Because the sequence of the pre-propeptide is as yet unavailable, it is not known whether or not it can be included among the cathelicidins. It has not been established whether or not the C. maenas 6.5 kDa peptide has antiviral activity.

The biogenic amines serotonin (5-HT) and octopamine (OA) have many roles in neurological systems in decapod crustaceans influencing processes as diverse as sensitivity of individual sensory neurons and agonistic behaviours. I examined aspects of the aminergic system in the squat lobster Munida quadrispina (Anomura, Galatheidae) and compared my results with data on aminergic systems and behaviours in more extensively studied species. M. quadrispina has a complex set of agonistic behaviours, and in comparisons with crayfish and lobster behaviour one major difference stands out: squat lobsters do not normally fight. Injecting carefully controlled doses of 5-HT induces M. quadrispina to perform stereotypical aggressive behaviours in the absence of any additional stimulation, and animals under the influence of injected 5-HT will fight. Animals under the influence of injected OA are much more likely to initiate escape responses to a standardized stimulus than are untreated animals, and assume, under certain circumstances, a submissive stance in the absence of additional external stimulation. The distributions of serotonergic and octopaminergic neurons in M. quadrispina are overall fairly similar to those of crayfish, lobsters, and crabs. However, several important differences, such as a lack of unpaired medial serontonergic neurons and far fewer octopaminergic “crotch” cells in M. quadrispina than in lobsters may relate to functional differences in the aminergic systems and other systems influenced by the amines. The pereiopod depressor muscles lift the body of the animal above the substrate and, therefore, are important in aggressive, and other behaviours. In M. quadrispina, as in all decapods, the depressor muscle and its antagonist, the levator muscle, are composed of multiple anatomically distinct heads. Most published studies have treated the depressor muscle as a single functional unit, despite documented differences in the population of depressor excitatory motor neurons. In M. quadrispina, each head has individualistic patterns of excitatory innervation, and the heads are activated differentially during walking and maintained stance. These differences reveal a functional subdivision among the heads of the depressor muscle, with different combinations of heads responsible for movement of the leg, stance maintenance, and joint tension. Injecting 5-HT into freely moving animals increases the excitatory input to all of the heads of the depressor muscle, whereas injecting OA decreases excitatory input. / Graduate

Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 114-132) Also available in print.

No description available.

Thesis (Ph.D.)--University of Hawaii at Manoa, 1994. / Includes bibliographical references (leaves 112-114). / Microfiche. / xi, 117 leaves, bound ill. 29 cm

Made available in DSpace on 2014-06-11T19:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-09Bitstream added on 2014-06-13T19:25:18Z : No. of bitstreams: 1 dallocco_pl_dr_rcla.pdf: 5863771 bytes, checksum: 49ba9f956f11d73624a21071be6a09c2 (MD5) / Universidade Estadual Paulista (UNESP) / O presente estudo aborda aspectos sistemáticos e biogeográficos das lagostas pertencentes as infraordens Achelata Scholtz & Richter, 1995 e Polychelida De Haan, 1841 que ocorrem no Oceano Atlântico. Constituindo um relevante recurso ecológico, comercial e científico, são encontradas em uma grande variedade de habitats e profundidades desde a região intertidal até a região abissal, ultrapassando os 5000m. De acordo com os dados obtidos através da literatura e da análise de exemplares provenientes de coleções carcinológicas nacionais e internacionais a fauna de lagostas (Achelata e Polychelida) do Oceano Atlântico é composta por 50 espécies, distribuídas em 3 famílias, 3 subfamílias e 18 gêneros. Para os táxons são fornecidas diagnoses e chaves de identificação, sendo que o tratamento formal de cada espécie inclui sinonímia, tipo(s), localidade-tipo, descrição, tamanho, coloração, hábitat, distribuição geográfica, observações, mapa de distribuição e ilustrações. O estudo biogeográfico realizado caracteriza e discute os padrões distribucionais encontrados, juntamente, com os fatores abióticos que influenciam na distribuição das espécies. São ainda analisados os graus de valência ecológica das espécies em relação aos tipos de substratos ocupados e gradientes batimétricos / This study addresses aspects of the systematics and biogeography of lobsters belonging to the infraorders Achelata Scholtz & Richter, 1995 and Polychelida De Haan, 1841 that occur in the Atlantic Ocean. Constituting an important ecological, commercial, and scientific resource, these lobsters are found in a wide variety of habitats and depths from the intertidal zone to the abyssal zone below 5000 m. According to published information and the analysis of specimens from carcinological collections within and outside Brazil, the lobster fauna (Achelata and Polychelida) in the Atlantic Ocean is composed of 50 species, belonging to 3 families, 3 subfamilies, and 18 genera. For the taxa, diagnoses and identification keys are provided. The formal treatment of each species includes the synonymy, type(s), type-locality, description, size, coloration, habitat, geographical distribution, notes, distribution map, and illustrations. The biogeographical study conducted characterizes and discusses the distributional patterns, along with the abiotic factors that influence the distributions of the species. The degrees of ecological valence of the species in relation to the types of substrates occupied and the bathymetric gradients are also analyzed

ix, 113 leaves : ill. ; 29 cm Typescript. (Another copy on microfilm is located in Archives) Thesis (Ph.D.) -- University of Oregon Includes vita and abstract Bibliography: leaves 106-113 University of Oregon theses, Dept. of Biology, Ph.D., 1978