Thesis (Ph.D.) - James Cook University, 2004. / Typescript (photocopy). Appendices : leaves 139-147. Bibliography: leaves 111-138.

Thesis (Ph. D.)--University of Cambridge, 1987. / Typescript.

1. The nervous system of cephalopod molluscs provides many unusual features which puzzle the biologist. Among these features is a system of nerves passing to the vena cava. Alexandrowicz proposed that this is a neurosecretory system. 2. Examination of the fine structure of the system in Eledone cirrosa shows that the nerves contain many types of vesicle, the most numerous being electron-dense vesicles of 80 - 150 nm diameter. The vesicles are concentrated in the nerve terminals which lie adjacent to the basement membrane found on the inner side of the blood vessel wall. The appearance of the nerves is similar to that of neurosecretory neurons found in both invertebrate and vertebrate nervous systems. Examination of the fine structure of the system in Sepia officinalis demonstrates that a similar arrangement is also present in this cephalopod. 3. Extracts of the vena cava of E. cirrosa exhibit potent pharmacological activity. This activity may be due to one or more active substances. When assayed on the isolated systemic heart of E. cirrosa the active substance causes an increase in amplitude and a prolonged increase in frequency of heartbeat. The regions of the blood vessel demonstrating this activity exactly parallel the distribution of the nerve terminals within the vena cava wall. 4. Structures within the nerve terminals may be isolated on a discontinuous sucrose gradient. It is found that the cardio-excitatory activity is associated with the electron-dense vesicles of 80 - 150 nm diameter. 5. Gel-filtration of vena cava extracts on Sephadex columns indicates that at least two active substances are present, one with a molecular weight less than 5,000 and one with a molecular weight greater than 5,000. 6. Various techniques, i.e. fluorescence histochemistry, spectro- photofluorimetry, and bioassay, reveal that the activity present in the extracts cannot be attributed to the presence of 5-hydroxy- tryptamine or catechol amines. 7. The active substance resists heating at an acid or alkaline pH, is unaffected by evaporation to dryness, and is extractable in organic solvents e.g. acetone. Further analysis is required before the chemical nature of the substance can be determined. 8. Release of the active substance could not be demonstrated to occur after electrical stimulation of the nerve trunks, or by changing the ionic environment of the nerve trunks. 9. The above results support Alexandrowicz' proposal that the nerves passing to the vena cava in Eledone citrosa form a neurosecretory system. The possible functions of this system are discussed.

Cefalópodes coleóides (lulas, sépias e polvos) produzem espermatóforos muito elaborados, os quais são transferidos à fêmea durante a cópula por meio de um apêndice modificado nos machos. Durante a transferência à fêmea, os espermatóforos sofrem, de forma autônoma, drásticas modificações na chamada \"reação espermatofórica\", complexo processo de evaginação do aparato ejaculatório, que conduz à exteriorização da massa espermática e corpo cimentante. Poucos trabalhos abordam com detalhes a morfologia e anatomia funcional dos espermatóforos dos cefalópodes, grande parte do conhecimento acerca da estrutura do espermatóforo tendo sido gerada por trabalhos clássicos do século XIX e início do século XX. Investigações acerca do funcionamento dos espermatóforos são consideravelmente mais raras, estando o conhecimento básico sobre a reação espermatofórica restrito a apenas 20 espécies de coleóides. Como o funcionamento extracorpóreo dos espermatóforos depende exclusivamente da intrincada estrutura e organização de seus componentes (e.g., membranas e túnicas), somente investigações detalhadas dessas estruturas proverão as bases para a compreensão do funcionamento e da exata função do complexo espermatóforo dos coleóides. Nesse contexto, a presente Tese, organizada em cinco capítulos, teve como objetivo principal investigar a estrutura e o funcionamento dos espermatóforos da lula Doryteuthis plei (Blainville, 1823). No primeiro capítulo, com o objetivo de se estudar a fundo a organização estrutural dos espermatóforos da espécie, diversas técnicas de microscopia foram testadas e empregadas. Como resultado da combinação de diferentes ferramentas de análise, a estrutura do espermatóforo revelou-se ainda mais complexa, sendo as principais descobertas referentes à: 1) elaborada estrutura da membrana mediana, organizada em camadas e apresentando um segmento aboral quimicamente distinto, que envolve parte do corpo cimentante; 2) presença de um material reticulado preenchendo o espaço entre a túnica interna e a membrana mediana (discute-se a possibilidade do mesmo consistir em um fluido viscoso em espermatóforos intactos); 3) presença de espículas intimamente associadas à membrana interna na região do corpo cimentante (além das espículas embebidas no filamento espiral); 4) presença de extensões membranosas que delimitam uma câmara pré-oral na região do capuz; e 5) complexa organização estrutural do corpo cimentante, delimitado por duas camadas e contendo substâncias de distintas propriedades químicas. Uma avaliação cuidadosa da literatura permite sugerir que pelo menos parte dessas características deva ser comum aos espermatóforos de outros loliginídeos, e, em alguns casos, de outros grupos de coleóides. Como parte da investigação acerca da reação espermatofórica e dos mecanismos envolvidos na fixação da massa espermática no corpo da fêmea, constatou-se que, sob condições artificiais, espermatóforos em evaginação são capazes de penetrar musculatura exposta, de forma similar ao fenômeno de \"implante profundo\" observado naturalmente em algumas lulas oceânicas. Esse resultado foi descrito no segundo capítulo, no qual foi levantada a hipótese de que um mecanismo de perfuração seria inerente à estrutura dos espermatóforos dos coleóides. Dando continuidade ao estudo da morfologia funcional dos espermatóforos de D. plei, o terceiro capítulo apresenta os resultados obtidos a partir da investigação do funcionamento do espermatóforo e da morfologia dos espermatângios (i.e, espermatóforos evertidos) obtidos in vitro, bem como daqueles naturalmente fixados na fêmea. As evidências reunidas permitem afirmar que o processo de fixação compreende distintas fases desempenhadas por diversos componentes do espermatóforo, contrariamente a um conceito anterior de que a fixação seria realizada somente por substâncias adesivas do corpo cimentante. Durante a reação espermatofórica, o aparato ejaculatório e respectivo filamento espiral são capazes de perfurar superficialmente ou escarificar o tecido-alvo. Subseqüentemente, o corpo cimentante sofre drástica modificação estrutural, resultando na extrusão de parte do conteúdo cimentante, o qual é injetado diretamente sobre o tecido perfurado. Além disso, o corpo cimentante é exteriorizado com uma extremidade afilada que, em alguns casos, foi encontrada firmemente implantada no tecido da fêmea, juntamente com as substâncias cimentantes. Concomitantemente ao processo de reconfiguração do corpo cimentante, a região da membrana interna que contém as espículas no espermatóforo intacto é evertida e estirada sobre a base do espermatângio, sugerindo um papel auxiliar no processo de fixação. Com base em evidências da literatura, bem como nas obtidas no âmbito da presente Tese, no quarto capítulo propõe-se um modelo teórico para explicar como o aparato ejaculatório em evaginação seria capaz de perfurar e implantar-se no corpo da fêmea durante a reação espermatofórica. Sugere-se que a perfuração seria mecânica e resultado da ação conjunta do aumento gradual do diâmetro dos anéis do filamento espiral e da distância entre os mesmos, bem como do poder de ancoragem proporcionado pelas respectivas espículas. Finalmente, o quinto capítulo apresenta uma revisão da literatura acerca do fenômeno de implante de espermatóforos em Decapodiformes, e reúne evidências que corroboram o modelo teórico proposto. Neste capítulo, é apresentada também uma reinterpretação da função da reação espermatofórica em Octopodiformes. Com base no levantamento de diversos caracteres reprodutivos, foi possível testar hipóteses de evolução da estrutura do espermatóforo e do sistema de implante dos espermatângios, bem como hipóteses de co-evolução de estruturas envolvidas no processo de transferência e armazenamento de espermatozóides. Duas hipóteses principais acerca da evolução do sistema de implante dos espermatângios são propostas. / Male coleoid cephalopods produce elaborate spermatophores, which are transferred to the female during mating. These spermatophores are capable of functioning autonomously and extracorporeally, undergoing complicated changes during the so-called spermatophoric reaction, i.e., a complex process of evagination of the spermatophoric tunics and membranes that, ultimately, leads to the extrusion and attachment of the sperm mass on the females body. Few detailed morphological studies regarding this structure have yet been conducted, and much of the knowledge on the coleoid spermatophore was generated by classical studies of the 19th and early 20th centuries; furthermore, investigations on the functioning of this structure are even rarer. Since the extracorporeal functioning of coleoid spermatophores must rely entirely on the intricate structure and organization of the tunics, membranes, and other structures composing the spermatophore, only detailed investigations of these components would provide the basis for comprehending its mechanics. On these grounds, the present five-chapter Thesis aimed to provide solid evidence that could allow for postulating hypothesis on the functioning and evolution of this unique structure. In the first chapter, an investigation of the morphology of the spermatophore of Doryteuthis plei (Blainville, 1823) applying several microscopy techniques was carried on. A much more complex structural arrangement was revealed for the loliginid spermatophore, the most striking findings being: 1) the complex, layered structure of the middle membrane, which bears an additional, chemically distinct segment surrounding part of the cement body; 2) the presence of a space between the inner tunic and middle membrane filled with a fine reticulated material, presumably a viscous fluid in the fresh state; 3) the presence of stellate particles not only embedded in the spiral filament, but also closely applied to the inner membrane at the level of the cement body; 4) the presence of a pre-oral chamber in the cap region; and 5) the complex organization of the cement body, formed by two distinct layers encompassing contents of different chemical and textural properties. Careful literature reassessment suggests several of these features are common to loliginids, and to some extent to other squids. Their possible functional implications are discussed in light of our knowledge on the spermatophoric reaction mechanics. As part of the investigation on the spermatophoric reaction, and the mechanisms involved in the attachment of the sperm mass on the females body, it was found that the everting spermatophore, when directed towards the incised region of an experimental tissue sample, was able to readily penetrate the artificially exposed musculature, almost resembling natural deep implantation observed in some oceanic and deep-sea squids; this finding is reported in the second chapter, where it was hypothesized that the mechanism involved in deep implantation could be inherent to the 215 spermatophore structure of all squids. The third chapter investigated the functional morphology of the spermatophore of the squid D. plei applying in vitro analysis of the reaction, as well as light and electron microscopy investigation of spermatangia (everted spermatophores containing the sperm mass) obtained either in vitro or naturally attached on the female. Hitherto unnoticed functional features of the loliginid spermatophore revealed herein required a reappraisal of some important processes involved in the spermatophoric reaction, as well as the proposal of new hypotheses to explain their mechanics. The most striking findings concern to the attachment mechanism, which is not carried out solely by cement adhesive material, as previously believed, but rather by a complex process performed by multiple structures that lead to the implantation of the base of the spermatangium into the female body. Firstly, the everting ejaculatory apparatus is presumably able to superficially puncture the female tissue. Subsequently to this process, the cement body passes through a complex structural rearrangement, which leads to the injection of both its viscid cement contents and pointed oral region through the puncture into the female tissue. When the inner membrane at the oral region of the cement body is everted, its sharp stellate particles are exposed, presumptively adhering to the scarified tissue and augmenting attachment by assuring the injection of the cement material inside the superficial hole. The functioning of the loliginid spermatophore is revisited in light of these findings. The forth chapter, building upon evidence from the literature along with evidence from these experiments, proposes a theoretical model to explain how the everting ejaculatory apparatus would be able to mechanically perforate, and concomitantly implant the spermatophore into the female body during the spermatophoric reaction. It is proposed that this process is achieved chiefly through the combination of 1) an \"evaginating-helix\" mechanism performed by the everting ejaculatory apparatus\' spiral filament, and 2) the anchorage provided by its numerous, minute sharp stellate particles. Finally, the fifth chapter reviews the literature concerning the phenomenon of implantation of spermatophores in decapodiforms, and presents evidence corroborating the proposed theoretical model ascribing the role of implantation to the mechanical perforation performed by the spiral filament. The mechanisms of spermatophore transfer are also reviewed for octopodiforms, and a reinterpretation of the function of the spermatophoric reaction in this case is provided. In light of parsimonious character optimizations performed onto recently published phylogenetic trees, a complete ejaculatory apparatus with a spiral filament, as well as the spermatophoric reaction, apparently emerged once and early in the evolution of the Coleoidea. This novelty possibly provided an efficient attachment mechanism and presumably countered the changes associated with the adoption of an active mode of life by coleoids, augmenting fertilization success. Two main hypotheses for the evolution of the complex spermatophore within Coleoidea and Decapodiformes are proposed.

Cistopus sp. is a medium to large octopod and it is common in the fish markets of Taiwan. The diagnostic character of the genus Cistopus is the possession of eight mucous pouches in the web between the base of each arm. However, researches on this special structure were absent. This study is to describe the morphological characters of Cistopus sp. from Taiwanese waters and to examine the mucous pouch histologically. The mitochondrial COI gene sequences are used as a tool to analyze the phylogenetic relationships between Cistopus and other genera of the family Octopodidae. Based on the results of this study, the Cistopus of Taiwanese waters is different from the genuine C. indicus and the Cistopus of the Andaman Sea. Cistopus sp. is widely distributed from coastal Asia to India at least and presents sexual dimorphism in the openings of the mucous pouches. The inner wall of the mucous pouches is composed of columnar epithelial cells, and the mucus is secreted from the epithelial cells. The substance secreted from the inner wall is acid mucopolysaccharides. According to the phylogenetic analysis of the octopods COI DNA sequences, Cistopus is grouped with other members of subfamily Octopodinae to form a monophyletic group.

Cefalópodes coleóides (lulas, sépias e polvos) produzem espermatóforos muito elaborados, os quais são transferidos à fêmea durante a cópula por meio de um apêndice modificado nos machos. Durante a transferência à fêmea, os espermatóforos sofrem, de forma autônoma, drásticas modificações na chamada \"reação espermatofórica\", complexo processo de evaginação do aparato ejaculatório, que conduz à exteriorização da massa espermática e corpo cimentante. Poucos trabalhos abordam com detalhes a morfologia e anatomia funcional dos espermatóforos dos cefalópodes, grande parte do conhecimento acerca da estrutura do espermatóforo tendo sido gerada por trabalhos clássicos do século XIX e início do século XX. Investigações acerca do funcionamento dos espermatóforos são consideravelmente mais raras, estando o conhecimento básico sobre a reação espermatofórica restrito a apenas 20 espécies de coleóides. Como o funcionamento extracorpóreo dos espermatóforos depende exclusivamente da intrincada estrutura e organização de seus componentes (e.g., membranas e túnicas), somente investigações detalhadas dessas estruturas proverão as bases para a compreensão do funcionamento e da exata função do complexo espermatóforo dos coleóides. Nesse contexto, a presente Tese, organizada em cinco capítulos, teve como objetivo principal investigar a estrutura e o funcionamento dos espermatóforos da lula Doryteuthis plei (Blainville, 1823). No primeiro capítulo, com o objetivo de se estudar a fundo a organização estrutural dos espermatóforos da espécie, diversas técnicas de microscopia foram testadas e empregadas. Como resultado da combinação de diferentes ferramentas de análise, a estrutura do espermatóforo revelou-se ainda mais complexa, sendo as principais descobertas referentes à: 1) elaborada estrutura da membrana mediana, organizada em camadas e apresentando um segmento aboral quimicamente distinto, que envolve parte do corpo cimentante; 2) presença de um material reticulado preenchendo o espaço entre a túnica interna e a membrana mediana (discute-se a possibilidade do mesmo consistir em um fluido viscoso em espermatóforos intactos); 3) presença de espículas intimamente associadas à membrana interna na região do corpo cimentante (além das espículas embebidas no filamento espiral); 4) presença de extensões membranosas que delimitam uma câmara pré-oral na região do capuz; e 5) complexa organização estrutural do corpo cimentante, delimitado por duas camadas e contendo substâncias de distintas propriedades químicas. Uma avaliação cuidadosa da literatura permite sugerir que pelo menos parte dessas características deva ser comum aos espermatóforos de outros loliginídeos, e, em alguns casos, de outros grupos de coleóides. Como parte da investigação acerca da reação espermatofórica e dos mecanismos envolvidos na fixação da massa espermática no corpo da fêmea, constatou-se que, sob condições artificiais, espermatóforos em evaginação são capazes de penetrar musculatura exposta, de forma similar ao fenômeno de \"implante profundo\" observado naturalmente em algumas lulas oceânicas. Esse resultado foi descrito no segundo capítulo, no qual foi levantada a hipótese de que um mecanismo de perfuração seria inerente à estrutura dos espermatóforos dos coleóides. Dando continuidade ao estudo da morfologia funcional dos espermatóforos de D. plei, o terceiro capítulo apresenta os resultados obtidos a partir da investigação do funcionamento do espermatóforo e da morfologia dos espermatângios (i.e, espermatóforos evertidos) obtidos in vitro, bem como daqueles naturalmente fixados na fêmea. As evidências reunidas permitem afirmar que o processo de fixação compreende distintas fases desempenhadas por diversos componentes do espermatóforo, contrariamente a um conceito anterior de que a fixação seria realizada somente por substâncias adesivas do corpo cimentante. Durante a reação espermatofórica, o aparato ejaculatório e respectivo filamento espiral são capazes de perfurar superficialmente ou escarificar o tecido-alvo. Subseqüentemente, o corpo cimentante sofre drástica modificação estrutural, resultando na extrusão de parte do conteúdo cimentante, o qual é injetado diretamente sobre o tecido perfurado. Além disso, o corpo cimentante é exteriorizado com uma extremidade afilada que, em alguns casos, foi encontrada firmemente implantada no tecido da fêmea, juntamente com as substâncias cimentantes. Concomitantemente ao processo de reconfiguração do corpo cimentante, a região da membrana interna que contém as espículas no espermatóforo intacto é evertida e estirada sobre a base do espermatângio, sugerindo um papel auxiliar no processo de fixação. Com base em evidências da literatura, bem como nas obtidas no âmbito da presente Tese, no quarto capítulo propõe-se um modelo teórico para explicar como o aparato ejaculatório em evaginação seria capaz de perfurar e implantar-se no corpo da fêmea durante a reação espermatofórica. Sugere-se que a perfuração seria mecânica e resultado da ação conjunta do aumento gradual do diâmetro dos anéis do filamento espiral e da distância entre os mesmos, bem como do poder de ancoragem proporcionado pelas respectivas espículas. Finalmente, o quinto capítulo apresenta uma revisão da literatura acerca do fenômeno de implante de espermatóforos em Decapodiformes, e reúne evidências que corroboram o modelo teórico proposto. Neste capítulo, é apresentada também uma reinterpretação da função da reação espermatofórica em Octopodiformes. Com base no levantamento de diversos caracteres reprodutivos, foi possível testar hipóteses de evolução da estrutura do espermatóforo e do sistema de implante dos espermatângios, bem como hipóteses de co-evolução de estruturas envolvidas no processo de transferência e armazenamento de espermatozóides. Duas hipóteses principais acerca da evolução do sistema de implante dos espermatângios são propostas. / Male coleoid cephalopods produce elaborate spermatophores, which are transferred to the female during mating. These spermatophores are capable of functioning autonomously and extracorporeally, undergoing complicated changes during the so-called spermatophoric reaction, i.e., a complex process of evagination of the spermatophoric tunics and membranes that, ultimately, leads to the extrusion and attachment of the sperm mass on the females body. Few detailed morphological studies regarding this structure have yet been conducted, and much of the knowledge on the coleoid spermatophore was generated by classical studies of the 19th and early 20th centuries; furthermore, investigations on the functioning of this structure are even rarer. Since the extracorporeal functioning of coleoid spermatophores must rely entirely on the intricate structure and organization of the tunics, membranes, and other structures composing the spermatophore, only detailed investigations of these components would provide the basis for comprehending its mechanics. On these grounds, the present five-chapter Thesis aimed to provide solid evidence that could allow for postulating hypothesis on the functioning and evolution of this unique structure. In the first chapter, an investigation of the morphology of the spermatophore of Doryteuthis plei (Blainville, 1823) applying several microscopy techniques was carried on. A much more complex structural arrangement was revealed for the loliginid spermatophore, the most striking findings being: 1) the complex, layered structure of the middle membrane, which bears an additional, chemically distinct segment surrounding part of the cement body; 2) the presence of a space between the inner tunic and middle membrane filled with a fine reticulated material, presumably a viscous fluid in the fresh state; 3) the presence of stellate particles not only embedded in the spiral filament, but also closely applied to the inner membrane at the level of the cement body; 4) the presence of a pre-oral chamber in the cap region; and 5) the complex organization of the cement body, formed by two distinct layers encompassing contents of different chemical and textural properties. Careful literature reassessment suggests several of these features are common to loliginids, and to some extent to other squids. Their possible functional implications are discussed in light of our knowledge on the spermatophoric reaction mechanics. As part of the investigation on the spermatophoric reaction, and the mechanisms involved in the attachment of the sperm mass on the females body, it was found that the everting spermatophore, when directed towards the incised region of an experimental tissue sample, was able to readily penetrate the artificially exposed musculature, almost resembling natural deep implantation observed in some oceanic and deep-sea squids; this finding is reported in the second chapter, where it was hypothesized that the mechanism involved in deep implantation could be inherent to the 215 spermatophore structure of all squids. The third chapter investigated the functional morphology of the spermatophore of the squid D. plei applying in vitro analysis of the reaction, as well as light and electron microscopy investigation of spermatangia (everted spermatophores containing the sperm mass) obtained either in vitro or naturally attached on the female. Hitherto unnoticed functional features of the loliginid spermatophore revealed herein required a reappraisal of some important processes involved in the spermatophoric reaction, as well as the proposal of new hypotheses to explain their mechanics. The most striking findings concern to the attachment mechanism, which is not carried out solely by cement adhesive material, as previously believed, but rather by a complex process performed by multiple structures that lead to the implantation of the base of the spermatangium into the female body. Firstly, the everting ejaculatory apparatus is presumably able to superficially puncture the female tissue. Subsequently to this process, the cement body passes through a complex structural rearrangement, which leads to the injection of both its viscid cement contents and pointed oral region through the puncture into the female tissue. When the inner membrane at the oral region of the cement body is everted, its sharp stellate particles are exposed, presumptively adhering to the scarified tissue and augmenting attachment by assuring the injection of the cement material inside the superficial hole. The functioning of the loliginid spermatophore is revisited in light of these findings. The forth chapter, building upon evidence from the literature along with evidence from these experiments, proposes a theoretical model to explain how the everting ejaculatory apparatus would be able to mechanically perforate, and concomitantly implant the spermatophore into the female body during the spermatophoric reaction. It is proposed that this process is achieved chiefly through the combination of 1) an \"evaginating-helix\" mechanism performed by the everting ejaculatory apparatus\' spiral filament, and 2) the anchorage provided by its numerous, minute sharp stellate particles. Finally, the fifth chapter reviews the literature concerning the phenomenon of implantation of spermatophores in decapodiforms, and presents evidence corroborating the proposed theoretical model ascribing the role of implantation to the mechanical perforation performed by the spiral filament. The mechanisms of spermatophore transfer are also reviewed for octopodiforms, and a reinterpretation of the function of the spermatophoric reaction in this case is provided. In light of parsimonious character optimizations performed onto recently published phylogenetic trees, a complete ejaculatory apparatus with a spiral filament, as well as the spermatophoric reaction, apparently emerged once and early in the evolution of the Coleoidea. This novelty possibly provided an efficient attachment mechanism and presumably countered the changes associated with the adoption of an active mode of life by coleoids, augmenting fertilization success. Two main hypotheses for the evolution of the complex spermatophore within Coleoidea and Decapodiformes are proposed.

Although the Red Sea presents a unique environment with high temperature and salinity, it remains an area that is understudied. This lack of information is reflected in many areas, one which is biodiversity. Despite increasing work on biodiversity throughout the Red Sea and an increase in Cephalopoda studies, Cephalopoda in the Red Sea remain underrepresented, which is especially pronounced in molecular analyses. Members of the class Cephalopoda are considered to be major contributors to coral reef ecosystems, serving as part of the food chain and exhibiting population increases due to targeted teleost fisheries and global climate change. In order to assess the biodiversity of Cephalopoda in the Saudi Arabian Red Sea, 87 specimens were collected from 25 reef locations between 17°N and 28°N latitude, as well as from the largest fish market in the Kingdom of Saudi Arabia. Taxonomic identification of specimens was determined using morphological comparisons with previously reported species in the Red Sea and the molecular barcoding region Cytochrome Oxidase I. 84 Red Sea sequences were compared with sequences from GenBank and analyzed using a complement of Neighbor-Joining, Maximum-Likelihood, and Bayesian inference trees. Species complexes were also investigated for Sepia pharaonis and Sepioteuthis lessoniana, which had been previously reported. From 17 cuttlefish, our study yielded three species, two of which matched previously reported species in GenBank. In addition, two distinct clades of Sepia pharaonis were identified. Of 35 squid collected, four species were identified, one of which did not match any other accepted species in literature, while Sepioteuthis lessoniana in the Red Sea formed a distinct clade. From 30 different specimens a total of five genera of Octopoda were present, forming six distinct species. Five Octopoda species collected did not match previously reported species, although many specimens were paralarvae or juveniles, so morphologically we could not compare to previously described species in the Red Sea. Cephalopoda fisheries in the Red Sea is low, and as their populations increase worldwide, this could be a viable fishery for Saudi Arabia. As such, further investigation into the role which cephalopods play in supporting biodiversity in the Red Sea is essential.

Made available in DSpace on 2014-06-12T18:00:43Z (GMT). No. of bitstreams: 2 arquivo2389_1.pdf: 2837538 bytes, checksum: f362e688363617268be0cd6dabfe8eea (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A Bacia da Paraíba desempenha um papel importante para elucidar a história do Atlântico Sul, uma vez que, integra o sistema de bacias marginais do leste sul-americano e foi à última porção a se separar durante fragmentação do Gondwana. O presente trabalho tem como objetivo o estudo dos amonóides da Bacia da Paraíba sob aspectos cronoestratigráficos, paleobiogeográficos e paleoecológicos. A metodologia empregada durante a realização da pesquisa foi divida nas seguintes etapas: levantamento do acervo paleontológico da coleção científica do DGEO-CTG-UFPE; trabalhos em laboratório, para preparação, identificação, classificação e catalogação do material; revisão taxonômica dos amonóides da bacia. Foram registradas para a formação quatro ordens de amonóides típicas do Cretáceo, sete gêneros e nove espécies: PHYLLOCERATINA Hypophylloceras (Neophylloceras) surya Forbes, 1846; LYTOCERATINA, Gaudryceras varicostatum van Hoepen, 1921; AMMONITINA, Hauericeras Grossouvre, 1894, Pachydiscus (Pachydiscus) jacquoti Seunes, 1890; Pachydiscus (Pachydiscus) neubergicus von Hauer, 1858; Sphenodiscus lobatus Tuomey, 1854; ANCYLOCERATINA, Axonoceras cf. compressum Stephenson, 1941; Axonoceras pingue Stephenson ?; Diplomoceras cylindraceum Defrance, 1816. Os amonóides da Bacia da Paraíba apresentam idades que vão do Campaniano superior ao Maastrichtiano. A espécie Pachydiscus (Pachydiscus) neubergicus é registrada pela primeira vez para a bacia. A paleofauna estudada apresenta freqüência que varia entre comum e raro, indica ambiente nerítico profundo de plataforma continental entre 100 e 200m para a bacia e 60% são cosmopolitas sendo registradas em todas as paleoprovíncias, apresenta também uma maior relação com a fauna sul americana e tetiana

This work examines the structural role of the ammonoid shell in supporting hydrostatic load and the role of shell shape in facilitating swimming. The history of studies of the role of the shell in supporting hydrostatic load is discussed first, and is followed by an analysis of the function of the septal suture. The discussion of swimming consists of a critique of the previous work which emphasized the use of Nautilus as a modem analogue for swimming in ammonoids. This is followed by a discussion of flow tank studies that I conducted to examine the role of shell shape in drag production and power consumption of swimming in ammonoids. It had long been thought that the the shells of chambered cephalopods served as buoyancy compensation devices. However, it was not until the 1960's that the internal pressure of the shell was demonstrated to be less than one atmosphere, and that the shell structure supports hydrostatic load. It is remarkable that the internal pressure of cephalopod shells was not ascertained until the 1960s. As early as 1832 the great anatomist Richard Owen called for an empirical investigation of this subject. Functional and adaptive explanations were in vogue in Owen's time as a consequence of William Paley's argument from design. During the late 19th and early 20th century adaptation and functional explanations were no longer emphasized in the interpretation of morphology; non-adaptive evolutionary ideas in vogue in this time period stressed the role of development as a guiding force. It was not until the mid 20th century that there was renewed interest in cephalopod functional morphology and the role of the shell in resisting implosion was ascertained. / Ph. D.

No description available.