No description available.

No description available.

The geographical and temporal distributions of the British Carboniferous Bryozoa have been determined, incorporating data from fieldwork (including localities in Scotland, North England, North Wales, South Wales, and Avon), museum collections, and literature searches. A total of 126 species has been recognised, though further work may reveal some synonymies within this list. The forty species collected during the fieldwork have been identified by reference to previous taxonomic work; most species can be assigned to established taxonomic descriptions, but two new species, Rhombopora bancrofti and Polypora hexagonaria, are proposed, and the descriptions of Rhombopora incrassata and Rhombopora similis are emended. The applicability of Student's t-test to the morphometric analysis of Carboniferous bryozoan species has been studied, and a computer program written to perforin this task, incorporating a database of species measurements. A new statistical method, the division t-test, is presented in this thesis; this method is useful in comparing the relative ratios of bryozoan colony parameters. Both the t-test and the division t-test were found to be of use in identifying bryozoan species. Analysis of the bryozoan faunas in nine regional areas of Britain has been made using the Simpson and Jaccard coefficients of similarity. The resulting coefficients are consistent with the limited distribution capability of many bryozoan taxa, and also match with the known palaeogeography and palaeocurrents of the Carboniferous of northwest Europe. Plots of species diversity against geographical distribution show a similar pattern to that produced by Tertiary non-planktotrophic larvae-bearing neogastropods. Further, additional plots of species diversity against species longevity produced a pattern consistent with normal background extinction events. A study of bryozoan morphology between different areas and different stages within the Carboniferous indicated that species showed no measurable temporal evolutionary or lateral geographical changes through the Lower Carboniferous. Rather, local environmental stresses are the major architects of bryozoan colony morphology.

Eighteen species of Bryozoa are described from the Upper Permian zechstein reef - they are assigned to ten genera in the Orders Fenestrata, Trepostomat and cyclostomata. Emended diagnoses are given at various levels and superspecific taxonomic categories within the Fenestrata are discussed. The examination of type specimens and of a large suite of new material has allowed the limits of intraspecific morphological variability to be defined and has resulted in the synonymising of several species. Three new taxa are described, for which holotypes have been designated :- Ryhopora delicata gen. nov., sp. nov. Acanthocladia magna sp. nov. and Penniretepora waltherinodata subsp. nov. The genera Penniretepora and Kalvariella Are recorded for the first time from the Zechstein reef in N.E. England. Aspects of bryozoan palaeobiology And functional morphology have been inferred at zooid and colony level. A type of ovicell, new in the Fenestrata, is described and is compared with those of the Cheilostomata; the taxonomic significance of this chAracter is assessecl. Patterns of zooid-generated feeding currents are inferred and some correlation of intraspecifically varying zoarial morphology with environment is suggested. The characteristic distribution of Bryozoa in relation to Zechstein reef sub-environments is described. An analysis of species abundance and diversity demonstrates a marked faunal impoverishment in reef-flat communities; new evidence for contemporaneous reef lithification is assessed.

O gênero Scrupocellaria senso lato (Família Candidae) compreende Ca. 92 espécies, 20 fósseis e 72 recentes. Muitas dessas espécies são morfologicamente semelhantes ou tratadas como tendo grande plasticidade morfológica, as quais consequentemente têm ampla distribuição mundial. Embora o gênero tenha uma longa história taxonômica e seus representantes sejam abundantes e comuns desde as regiões entremares até mais de 1,000 metros de profundidade, estudos taxonômicos do gênero são escassos. Os objetivos desse estudo são: (i) realizar o levantamento das espécies de Scrupocellaria, (ii) delimitar a variação morfológica intraespecífica das espécies, (iii) analisar a morfologia comparada de Scrupocellaria visando propor uma hipótese de relações filogenéticas entre as espécies do gênero. O estudo inclui colônias coletadas em vários pontos da costa brasileira, bem como espécimes depositados em coleções científicas nacionais e internacionais. Alguns espécimes foram selecionados para observação em Microscópio Eletrônico de Varredura. Entre os espécimes estudados foram incluídos 32 holótipos, sintipos de 22 espécies e 1 lectótipo. Várias estruturas morfológicas foram utilizadas pela primeira vez na distinção dos táxons, e.g. forma da superfície dos rizoides, tamanho dos vibraculários basais, tamanho e forma dos aviculários frontais e laterais. O lectótipo de Scrupocellaria reptans foi escolhido para redefinir a identidade dos espécimes descritos por Carolus Linnaeus, distintos de uma nova espécie descrita para o Mar do Norte pela forma do escudo, tamanho dos zooides e rizoides cilíndricos sem ganchos em sua superfície. Scrupocellaria jolloisii é relatada pela primeira vez no Atlântico e classificada no gênero Licornia, nome que é ressuscitado para incluir outras 9 espécies: Licornia annectens n. comb., Licornia cervicornis n. comb., Licornia cyclostoma n. comb., Licornia diadema n. comb., Licornia ferox n. comb., Licornia gaspari n. comb., Licornia longispinosa n. comb., Licornia macropora n. comb. e Licornia prolata n. comb. Um novo gênero, N.gen.1, é criado para acomodar Scrupocellaria bertholletii (Audouin, 1826). Outras 26 espécies, 19 das quais descritas como novas, são classificadas em N.gen.1, e uma chave dicotômica para as espécies do gênero é apresentada. Um estudo filogenético, baseado em 35 caracteres morfológicos de 84 espécies de Candidae, indica que o gênero Scrupocellaria compreende um táxon polifilético e que o gênero N.gen.1 é monofilético. Scrupocellaria \'sensu stricto\' é redefinido utilizando quatro características morfológicas: câmara vibracular com sulco do vibráculo curvo e obliquo, ectooécio com fenestra frontal, 2 vibraculários axiais e opérculo membranoso com margem distal distinta. Assim, Scrupocellaria \'sensu stricto\' inclui 10 espécies: Scrupocellaria aegeensis, Scrupocellaria delilii, Scrupocellaria harmeri, Scrupocellaria incurvata, Scrupocellaria inermis, Scrupocellaria intermedia, Scrupocellaria jullieni, Scrupocellaria minuta, Scrupocellaria scrupea, e Scrupocellaria scruposa. Cinco gêneros são criados para acomodar outras espécies classificadas anteriormente como Scrupocellaria, distintos pela forma do escudo e espinhos orais, forma do vibraculários e forma dos ovicelos. O presente estudo revelou uma diversidade ainda desconhecida para vários grupos de Candidae, e mostra a necessidade de mais estudos sobre a taxonomia e filogenia da família, para a melhor compreensão da distribuição, variação morfológica e relação filogenética entre os táxons / The genus Scrupocellaria sensu lato (Family Candidae) comprises about 92 species, 20 fossil and 72 Recent. Many of the species are morphologically similar or have been treated taxonomically as having a high degree of morphological plasticity, with distributions of many of the species being reported to be \"worldwide\". Despite the long taxonomic history of Scrupocellaria and its occurrence in habitats ranging from intertidal to deep water, taxonomic studies of the genus are scarce. Therefore the purpose of this study was: (i) to carry out a species survey of Scrupocellaria, (ii) to delimit the intraspecific morphological variations of species, (iii) to analyze the comparative morphology of Scrupocellaria in order to propose a hypothesis of phylogenetic relationships between species of the genus. This study included both colonies collected in various localities on Brazilian coast and material of non-Brazilian species deposited at scientific collections around the world. All specimens were studied by light microscopy. Some specimens were also chosen for study with the scanning electron microscope. Specimens studied included holotypes of 32 species, syntypes of 22 species and 1 lectotype. Some morphological characters were used for the first time to distinguish taxa, e.g. rhizoidal surface, size of abfrontal vibracula, and shape of lateral and frontal avicularia. The lectotype of Scrupocellaria reptans was selected to redescribe and define the identity of the type species of Scrupocellaria from specimens described by Carolus Linnaeus, and to show its distinction from a newly described species from North Sea by means of the shape of scuta, size of zooids and, occurence of rhizoids with retroussé hooks. Scrupocellaria jolloisii is reported by first time in the Atlantic Ocean and placed in the genus Licornia, a name resurrected to acommodate 9 species formerly placed in Scrupocellaria: Licornia annectens n. comb., Licornia cervicornis n. comb., Licornia cyclostoma n. comb., Licornia diadema n. comb., Licornia ferox n. comb., Licornia gaspari n. comb., Licornia longispinosa n. comb., Licornia macropora n. comb. e Licornia prolata n. comb. A new genus, N.gen.1, is described to include Scrupocellaria bertholletii. Twenty-six species, 19 of them described as new, are assigned to N.gen.1, and a taxonomic key for species of that genus is presented. A phylogenetic study using 35 morphological characters of 84 Candidae species suggests that the genus Scrupocellaria is a polyphyletic taxa and the genus N.gen.1 is a monophyletic taxa. Scrupocellaria \'sensu stricto\' is redefined according to four morphological features: vibracular chamber with curved setal groove, ooecium with a single ectooecial fenestra, two axillary vibracula and a membranous operculum with a distinct distal rim. Thus Scrupocellaria \'sensu stricto\' includes 10 species: Scrupocellaria aegeensis, Scrupocellaria delilii, Scrupocellaria harmeri, Scrupocellaria incurvata, Scrupocellaria inermis, Scrupocellaria intermedia, Scrupocellaria jullieni, Scrupocellaria minuta, Scrupocellaria scrupea, and Scrupocellaria scruposa. Five genera are erected to include other species previously assigned to Scrupocellaria; they are distinct in the shape of scuta and oral spines, the shape of vibracular chamber and the surface of ovicells. The study revealed a high diversity in some groups of Candidae and the necessity of additional studies on taxonomy and phylogeny of the family to provide a better understanding of distributions, morphological variation, and phylogenetic relationships between the taxa

In the present research several aspects of the reproductive biology of the marine hermaphroditic bryozoan, Celleporell hyalin (Linnaeus, 1767) were investigated. First (see Chapter 2), aliquots, of different ages from a stock of allosperm suspension were used to fertilize a series of virgin ramets, so characterizing the decay in fertility of released sperm and any effects of sperm ageing on subsequent embryogenesis and larval metamorphosis. The effect of temperature on the above variables was also investigated. The fertile half-life of C. hvalina sperm was about 1-2 h, although significant decay in fertility occurred within a few minutes after release. Sperm ageing showed no deleterious effects on embryogenesis, larval viability, or metamorphosis. No clear effects of temperature on sperm ageing and fertilization success were found. Allosperm. storage was studied in colonies of C. hyalina. (L. ) under several experimental conditions (see Chapter 3). Recipient virgin colonies were exposed to sexually compatible allosperm suspension and the appearance of the last newly ovulated oocytes in the coelorn. was used to assess duration of sperm storage. The same experiments examined continuation of brooding cycle and brooding success throughout the period of allosperm storage. Similar obserVations were conducted on wild colonies of C. hyalina taken from the field and kept in reproductive isolation in the laboratory. Production of progeny in females zooids budded beyond the original colonial growing edge was taken as evidence of sperm movement. The results of the present study show that recipient colonies continue producing coelomic oocytes up to 5 weeks after exposure to allosperm suspension. Moreover, the progeny were produced not only by female zooids present at the moment of allosperm dosage but also by female zooids, budded later, beyond the limit of the original growing edge. Since oocytes were not present in control colonies exposed to selfsperm, the results of the present study indicate that recipient colonies store sexually compatible allosperm and transport them within the colony in order to produce viable progeny. The effect of water flow on both sperm release and fertilization success in colonies of C. hyalin (L. ) was studied (see Chapter 4). Maximum numbers of released sperm were found at low and zero water velocities. Moreover, protruded male lophophores were observed only under those conditions. Fertilization success was studied in virgin colonies of C. hyalina (L. ) exposed to compatible allosperm suspensions under different feeding activity and water flow conditions. Fertilization success was higher in colonies with more active feeding autozooids than in those with fewer feeding autozooids. High water flow conditions induced reduction in the proportion of protruded lophophores, and reduced the frequency of ovicells bearing progeny. Moreover, in all the experiments offspring were concentrated in areas of the colony bearing active feeding autozooids. The results of this study suggest that sperm release take place under similar conditions that enhance cross fertilization, with a possible role of feeding activity in bringing sperm to the proximity of receiver colonies. Sperm competition and female choice was investigated in virgin colonies of C. hyalin (L. ) exposed to sexually compatible allosperm cocktails (see Chapter 5). A microsatellite-based. genotyping system was used to determine paternity. Progeny were mainly the product of outcrossing. In a few cases, a small proportion of progeny was attributed to selffertilization. These results suggest that outcrossing is the main reproductive strategy in this species and that neither selective female choice nor sperm competition occur in C. hyalin . Cryptic incompatibility allowing a flexible mating strategy to produce out-crossed progeny Z) in the presence of allospenn and selfing when they were absent was not found. The effects of mating sequence and temporal interval between matings (2 or 48 h) on sperm precedence in double-mated individuals were studied (see Chapter 6). Paternity was determined by using a microsatellite-based genotyping system. Settled colonies produced after short mating showed evidence of sperm mixing and first-male precedence. However, last colonies produced after both short and long mating intervals showed evidence of first-male precedence. When analyses were conducted using all the sampled progeny, low incidence of paternity by the second sperm donor (P2) and absence of self fertilization were found. No effect of mating order on success of the second donor was found. Prevalence of outcrossing was also found. These results suggest that first-male precedence in C. hyalin may promote outcrossing under sperm limitation conditions, by acceptance of the first compatible allosperm to become available. The effects of exposure to sperm suspensions and stressors on sexual allocation in colonies were studied (see Chapter 7). In the first experiment the effect of a waterborne factor on receptor colonies was studied. Adult colonies were exposed to compatible allosperm suspensions that had been filtered through 0.45 Vrn pores potentially able to remove cellular sized particles. As a control, receptor colonies were exposed to non-filtered allosperin suspensions. Appearance and growth of oocytes occurred only in the coelorn. of the control colonies. The active factor is not a dissolved molecule, but a particle that can be removed from water by filtration through 0.45 [im pores. This result plus the absence of developing oocytes in the receptor colonies exposed to similar concentration of selfsperm, suggest the operation of self/honself recognition and an important and active role of allosperm in initiating colonial reproductive investment in C. hyalina. Prevention of colonial growth and others stressors were associated with production of basal male zooids. In other experiments, exposure to sperm suspensions of different degrees of genetic relatedness showed a virtual absence of production of progeny in those colonies exposed to closely related sperm (i. e. self and halfsibs). Finally, in experiments with sexually immature colonies, the onset of sexual reproduction was triggered by exposure to allosperm, resulting in the production of female zooids even before the appearance of male zooids. Contacts between colonies of different genetic relatedness were studied under laboratory conditions (see Chapter 8). Moreover, observations were made on colonies growing on their natural substrata. Five types of responses were observed, from total fusion to overgrowth. Maximum degree of fusion, or morphological fusion, was manifested as morphologic interconnection between the ad oining colonies (i. e. production of coalescent zooids). Fusion occurred in all contacts between colonies of the same genotype, between parental colonies and their progeny and, between full and half sib colonies. In most cases the production of coalescent zooids was found. Absence of fusion occurred in all contacts between unrelated colonies and between some of the half sibs. Observations on wild colonies growing in contact with each other failed to reveal any incidences of coalescence. Non-aggressive overgrowth was confined to dead areas of one colony overgrown by zooids of the other healthy colony, independent of the genetic relatedness of the pairs. Differences in the fusibility between isocontact and allocontact suggest that colony specificity exists in C. hyalin , as has been found in other sessile colonial marine organisms.

O gênero Scrupocellaria senso lato (Família Candidae) compreende Ca. 92 espécies, 20 fósseis e 72 recentes. Muitas dessas espécies são morfologicamente semelhantes ou tratadas como tendo grande plasticidade morfológica, as quais consequentemente têm ampla distribuição mundial. Embora o gênero tenha uma longa história taxonômica e seus representantes sejam abundantes e comuns desde as regiões entremares até mais de 1,000 metros de profundidade, estudos taxonômicos do gênero são escassos. Os objetivos desse estudo são: (i) realizar o levantamento das espécies de Scrupocellaria, (ii) delimitar a variação morfológica intraespecífica das espécies, (iii) analisar a morfologia comparada de Scrupocellaria visando propor uma hipótese de relações filogenéticas entre as espécies do gênero. O estudo inclui colônias coletadas em vários pontos da costa brasileira, bem como espécimes depositados em coleções científicas nacionais e internacionais. Alguns espécimes foram selecionados para observação em Microscópio Eletrônico de Varredura. Entre os espécimes estudados foram incluídos 32 holótipos, sintipos de 22 espécies e 1 lectótipo. Várias estruturas morfológicas foram utilizadas pela primeira vez na distinção dos táxons, e.g. forma da superfície dos rizoides, tamanho dos vibraculários basais, tamanho e forma dos aviculários frontais e laterais. O lectótipo de Scrupocellaria reptans foi escolhido para redefinir a identidade dos espécimes descritos por Carolus Linnaeus, distintos de uma nova espécie descrita para o Mar do Norte pela forma do escudo, tamanho dos zooides e rizoides cilíndricos sem ganchos em sua superfície. Scrupocellaria jolloisii é relatada pela primeira vez no Atlântico e classificada no gênero Licornia, nome que é ressuscitado para incluir outras 9 espécies: Licornia annectens n. comb., Licornia cervicornis n. comb., Licornia cyclostoma n. comb., Licornia diadema n. comb., Licornia ferox n. comb., Licornia gaspari n. comb., Licornia longispinosa n. comb., Licornia macropora n. comb. e Licornia prolata n. comb. Um novo gênero, N.gen.1, é criado para acomodar Scrupocellaria bertholletii (Audouin, 1826). Outras 26 espécies, 19 das quais descritas como novas, são classificadas em N.gen.1, e uma chave dicotômica para as espécies do gênero é apresentada. Um estudo filogenético, baseado em 35 caracteres morfológicos de 84 espécies de Candidae, indica que o gênero Scrupocellaria compreende um táxon polifilético e que o gênero N.gen.1 é monofilético. Scrupocellaria \'sensu stricto\' é redefinido utilizando quatro características morfológicas: câmara vibracular com sulco do vibráculo curvo e obliquo, ectooécio com fenestra frontal, 2 vibraculários axiais e opérculo membranoso com margem distal distinta. Assim, Scrupocellaria \'sensu stricto\' inclui 10 espécies: Scrupocellaria aegeensis, Scrupocellaria delilii, Scrupocellaria harmeri, Scrupocellaria incurvata, Scrupocellaria inermis, Scrupocellaria intermedia, Scrupocellaria jullieni, Scrupocellaria minuta, Scrupocellaria scrupea, e Scrupocellaria scruposa. Cinco gêneros são criados para acomodar outras espécies classificadas anteriormente como Scrupocellaria, distintos pela forma do escudo e espinhos orais, forma do vibraculários e forma dos ovicelos. O presente estudo revelou uma diversidade ainda desconhecida para vários grupos de Candidae, e mostra a necessidade de mais estudos sobre a taxonomia e filogenia da família, para a melhor compreensão da distribuição, variação morfológica e relação filogenética entre os táxons / The genus Scrupocellaria sensu lato (Family Candidae) comprises about 92 species, 20 fossil and 72 Recent. Many of the species are morphologically similar or have been treated taxonomically as having a high degree of morphological plasticity, with distributions of many of the species being reported to be \"worldwide\". Despite the long taxonomic history of Scrupocellaria and its occurrence in habitats ranging from intertidal to deep water, taxonomic studies of the genus are scarce. Therefore the purpose of this study was: (i) to carry out a species survey of Scrupocellaria, (ii) to delimit the intraspecific morphological variations of species, (iii) to analyze the comparative morphology of Scrupocellaria in order to propose a hypothesis of phylogenetic relationships between species of the genus. This study included both colonies collected in various localities on Brazilian coast and material of non-Brazilian species deposited at scientific collections around the world. All specimens were studied by light microscopy. Some specimens were also chosen for study with the scanning electron microscope. Specimens studied included holotypes of 32 species, syntypes of 22 species and 1 lectotype. Some morphological characters were used for the first time to distinguish taxa, e.g. rhizoidal surface, size of abfrontal vibracula, and shape of lateral and frontal avicularia. The lectotype of Scrupocellaria reptans was selected to redescribe and define the identity of the type species of Scrupocellaria from specimens described by Carolus Linnaeus, and to show its distinction from a newly described species from North Sea by means of the shape of scuta, size of zooids and, occurence of rhizoids with retroussé hooks. Scrupocellaria jolloisii is reported by first time in the Atlantic Ocean and placed in the genus Licornia, a name resurrected to acommodate 9 species formerly placed in Scrupocellaria: Licornia annectens n. comb., Licornia cervicornis n. comb., Licornia cyclostoma n. comb., Licornia diadema n. comb., Licornia ferox n. comb., Licornia gaspari n. comb., Licornia longispinosa n. comb., Licornia macropora n. comb. e Licornia prolata n. comb. A new genus, N.gen.1, is described to include Scrupocellaria bertholletii. Twenty-six species, 19 of them described as new, are assigned to N.gen.1, and a taxonomic key for species of that genus is presented. A phylogenetic study using 35 morphological characters of 84 Candidae species suggests that the genus Scrupocellaria is a polyphyletic taxa and the genus N.gen.1 is a monophyletic taxa. Scrupocellaria \'sensu stricto\' is redefined according to four morphological features: vibracular chamber with curved setal groove, ooecium with a single ectooecial fenestra, two axillary vibracula and a membranous operculum with a distinct distal rim. Thus Scrupocellaria \'sensu stricto\' includes 10 species: Scrupocellaria aegeensis, Scrupocellaria delilii, Scrupocellaria harmeri, Scrupocellaria incurvata, Scrupocellaria inermis, Scrupocellaria intermedia, Scrupocellaria jullieni, Scrupocellaria minuta, Scrupocellaria scrupea, and Scrupocellaria scruposa. Five genera are erected to include other species previously assigned to Scrupocellaria; they are distinct in the shape of scuta and oral spines, the shape of vibracular chamber and the surface of ovicells. The study revealed a high diversity in some groups of Candidae and the necessity of additional studies on taxonomy and phylogeny of the family to provide a better understanding of distributions, morphological variation, and phylogenetic relationships between the taxa

The chemical study of three New Zealand marine organisms is described, along with a survey of the chemistry and biological activity of eighty-five marine organisms collected from New Zealand waters. The study of the New Zealand marine bryozoan Pterocella vesiculosa has resulted in the isolation of three new compounds; pterocellin H, pterocellin I and 1-methyl-5-bromo-8-methoxy-β-carboline. These compounds were characterised using high resolution mass spectrometry, one- and two-dimensional nuclear magnetic resonance spectroscopy and X-ray crystallography. The biological activity of these compounds was investigated and a discussion of the results including a comparison with the activity of closely related compounds is also presented. The crude extracts of eighty-five marine organisms were surveyed to establish their biological activity and chemical constituents. The results of this study indicated which species had interesting biological activity. The chemical survey allowed geographical and intra-species comparisons of chemical constituents between samples, as well as potentially indicating the presence of known secondary metabolites. For the Pterocella vesiculosa samples the survey methodology clearly illustrated the presence of pterocellins A and B. Two marine organisms were chosen for further investigation based on their biological activity and chemical survey results. Bioactivity directed isolation procedures yielded no new compounds from the organisms. The sterol composition of these species is also presented.

In the Indian River Lagoon, the nudibranch Okenia zoobotryon and its egg masses are found attached to the bryozoan Zoobotryon verticillatum throughout the year. Okenia zoobotryon is thought to live, feed, and reproduce exclusively on Z. verticillatum, which would make this a very specialized predator-prey interaction. The primary goal of my study was to document certain aspects of the ecological and chemical relationships between Z. verticillatum and O. zoobotryon. Specifically, I wanted to understand the cues used by the nudibranch to locate and remain on Z. verticillatum. Population surveys on Z. verticillatum, as well as other potential hosts, were performed. From these surveys, I found a small number of O. zoobotryon adults and egg masses on the red macroalga S. filamentosa mixed with Z. verticillatum (0.01 and 0.05 g/wet-weight, respectively), none on the bryozoan Amathia distans, and none on the red macroalga Gracilaria tikvahiae. To determine if prey identification was associated with an adult cue, I ran paired-choice trials. In these, the adults did not significantly prefer Z. verticillatum. Next, laboratory culture of larvae of O. zoobotryon was performed. During larval culture some aspects of this previously undocumented life-history were recorded; adults of this species developed from planktotrophic veliger larvae that hatched out of egg masses between 4 and 6 days, the time post-hatching to settlement was 7-8 days, and metamorphosis occurred approximately 24 hours after settlement. The final question addressed in this study was; "Does O. zoobotryon feed on and take up chemicals from Z. verticillatum?" To address this question, high-performance liquid chromatography was performed on extracts of Z. verticillatum and O. zoobotryon. Both organisms were compared and found to contain similar compounds, which suggest that the nudibranch is feeding on Z. verticillatum and taking up chemicals. Concentrations of compounds in Z. verticillatum varied between populations in the northern and southern regions of the Indian River Lagoon. There are, also, differences between the chemical composition of Z. verticillatum in the IRL (northern and southern) and the California species identified by Sato and Fenical (1983).

The Chatham Islands are located in the SW Pacific Ocean, approximately 850 km to the east of the South Island of New Zealand. This small group of islands is situated near the eastern margin of the Chatham Rise, an elongated section of submerged continental crust that represents part of the Late Paleozoic-Mesozoic Gondwana accretionary margin. The location and much of the geology of the Chatham Islands are attributed to intra-plate basaltic volcanism, initiated during the Late Cretaceous, in association with development of a failed rifting system to the south of the Chatham Rise. Despite the volcanic nature of much of the geology, the majority of the Cenozoic sedimentary stratigraphic record on the islands comprises non-tropical skeletal carbonate deposits whose deposition was often coeval with submarine volcanics and volcaniclastic deposits. This has resulted in complex stratigraphic relationships, with the volcanic geology exerting a strong influence on the geometry and distribution of the carbonate deposits. These limestones, despite some general field descriptions, have been little studied and are especially poorly understood from a petrographic and diagenetic perspective. The carbonate geology in detail comprises eleven discrete limestone units of Late Cretaceous through to Pleistocene age which were studied during two consecutive field expeditions over the summers of 2005 and 2006. These limestone occurrences are best exposed in scattered coastal outcrops where they form prominent rugged bluffs. While many of the younger (Oligocene to Pliocene) outcrops comprise of poorly exposed, thin and eroded limestone remnants (it;5 m thick), older (Late Paleocene to Early Oligocene) exposures can be up to 100 m in thickness. The character of these limestones is highly variable. In outcrop they display a broad range of textures and skeletal compositions, often exhibit cross-bedding, display differing degrees of porosity occlusion by cementation, and may include rare silicified horizons and evidence of hardground formation. Petrographically the limestones are skeletal grainstones and packstones with a typical compositional makeup of about 70% skeletal material, 10% siliciclasts, and 20% cement/matrix. Localised increases in siliciclastics occur where the carbonates are diluted by locally-derived volcaniclastics. The spectrum of skeletal assemblages identified within the Chatham Island limestones is diverse and appears in many cases to be comparable to the bryozoan dominant types common in mainland New Zealand and mid-latitude Australian cool-water carbonates in general. However, some key departures from the expected cool-water carbonate skeletal makeup have been identified in this study. The occurrence of stromatolitic algal mats in Late Cretaceous and Early Eocene carbonate deposits indicates not cool-temperate, but certainly warm-temperate paleoclimatic conditions. A change to cool-temperate conditions is recorded in the limestone flora/fauna from the mid-Late Miocene times following the development and later northward movement of the Subtropical Front. An uncharacteristic mix of shallow-shelf (bryozoans) and deeper water fauna (planktic foraminifera), together with their highly fragmented and abraded nature, is indicative of the likely remobilisation and redistribution of carbonate, primarily during episodic storm events. The Chatham Islands limestones formed within the relative tectonic stability of an oceanic island setting, which was conducive to ongoing carbonate accumulation throughout much of the Cenozoic. This contrasts markedly with other mainland New Zealand shelf carbonates which formed over sporadic and short-lived geological periods, experiencing greater degrees of burial cementation controlled by a relatively more active tectonic setting. As a consequence of the tectonically stable setting, the Chatham Islands limestones have experienced little burial and exhibit a paucity of burial cementation effects. They remain commonly soft and friable. Detailed petrographic investigations have shown the limestones are variably cemented by rare uneven acicular spar fringes, poorly to well-developed syntaxial rim cements about echinoderm fragments, and equant/blocky microsparite. Staining of thin sections and cathodoluminescence petrography show these spar cement generations are non-ferroan and their very dull- to non-luminescent nature supports precipitation from Mn-poor oxygenated waters, likely of an either meteoric or combined marine/shallow burial origin. Micrite is the dominant intra- and inter-particle pore fill and occurs both as a microbioclastic matrix and as precipitated homogenous and/or micropeloidal cement. The rare fringing cements often seen in association with homogenous and/or micropeloidal micrite may be indicative of true early marine (seafloor) cement precipitation and localised hardground development. An interesting feature of the geology of the Chatham Islands is the occurrence of carbonate material within sedimentary dykes. The locations of the dykes are in association with volcanic and volcaniclastic deposits. Similarities between dyke characteristics at Red Bluff on Chatham Island with mainland occurrences from East Coast and Canterbury Basins (North and South Islands, respectively) on mainland New Zealand have been recognised. They show complex structures including sidewall striations, internal flow structures as revealed by grain sorting, and extra-clast inclusions of previous fill lithologies which are characteristic of carbonate injection. This is in contrast to other dykes which are known to be of a passive fill origin. Multiple phases of carbonate sediment injection can be recognised by crosscutting relationships enabling the determination of a parasequence of events. Possible injection mechanisms are most likely associated with sediment overloading or hydrothermal pressurisation associated with emplacement of submarine volcanics. The Chatham Islands provide an exciting example of a geologically unique and complex non-tropical carbonate depositional setting. The production of carbonates is controlled by volcanic and volcaniclastic sediment input with the types of carbonate deposits and water depth variations related to thermal uplift/subsidence in association with global eustatic sealevel and temperature changes associated with development of Southern Ocean water fronts from the Late Cretaceous-Cenozoic. Carbonate deposition on the Chatham Islands is considered to relate to a rather variable and small scale oceanic, high energy, cool-water carbonate ramp setting whose geometry was continually evolving/changing as a consequence of periodic volcanic episodes.