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During the period the sponges described herein were which were used only sporadically in the past and were collected (1963-7), the author was a Research Associate regarded as of marginal value until two decades ago, at the Department of Geology, University of Illinois, paleontology and embryology, are now receiving great participating in a research project on carbonate attention. They have already brought drastic revisions to sediments of the Bimini area, directed by Prof. William systematics, with regard to redefinition and classification W. Hay (Department of Geology, University of Illinois. of higher taxa. Other approaches have recently emerged utilizing biochemistry, histology, cytology, autecology, now at the Rosenstiel School of Marine and Atmospheric and zoogeography, and these promise significant ad Science, University of Miami) and supported by the National Science Foundation. The objective of this pro vance in the delimitation and classification oflower taxa. ject was a study of the relationship between the carbo The rapidly changing state of sponge taxonomy is reflect nate sediments of the Bimini area and the benthonic ed in the paucity of definitive (i. e. widely accepted) revisions of genera and families. The lack of stability and fauna and flora, especially with regard to skeletal ele ments contributed to the sediment.
During the period the sponges described herein were which were used only sporadically in the past and were collected (1963-7), the author was a Research Associate regarded as of marginal value until two decades ago, at the Department of Geology, University of Illinois, paleontology and embryology, are now receiving great participating in a research project on carbonate attention. They have already brought drastic revisions to sediments of the Bimini area, directed by Prof. William systematics, with regard to redefinition and classification W. Hay (Department of Geology, University of Illinois. of higher taxa. Other approaches have recently emerged utilizing biochemistry, histology, cytology, autecology, now at the Rosenstiel School of Marine and Atmospheric and zoogeography, and these promise significant ad Science, University of Miami) and supported by the National Science Foundation. The objective of this pro vance in the delimitation and classification oflower taxa. ject was a study of the relationship between the carbo The rapidly changing state of sponge taxonomy is reflect nate sediments of the Bimini area and the benthonic ed in the paucity of definitive (i. e. widely accepted) revisions of genera and families. The lack of stability and fauna and flora, especially with regard to skeletal ele ments contributed to the sediment.
In the course of the last century a considerable amount of scientific work has been carried out in the Cayman Islands. The results of this (outlined in Chapter 1) are widely distributed in unpublished reports, university theses, various scientific publications and books, many of these sources being difficult to find and some now unobtainable. The purpose of this book, therefore, is to bring all this scattered information together and to present a coherent account of the biogeography and ecology of the Islands, as an easily available reference source and as a foundation on which future work can be based.
With contributions by E.Abraham, D.Barnes, R.Carpenter, L.Collado, P.Dodds, S.Dudgeon, D.Garbary, S.Gatti, B.Helmuth, M.R.Koehl, H.Lasker, R.Merks., W.Müller, S.Muko, B. Rinkevich, J.Sanchez, P.Sloot, M.Vermeij
Life began in the sea, and even today most of the deep diversity of the planet is marine. This is often forgotten, especially in tropical countries like Costa Rica, renowned for their rain forests and the multitude of life forms found therein. Thus this book focusing on marine diversity of Costa Rica is particularly welcome. How many marine species are there in Costa Rica? The authors report a total of 6,777 species, or 3. 5% of the world’s total. Yet the vast majority of marine species have yet to be formally described. Recent estimates of the numbers of species on coral reefs range from 1–9 million, so that the true number of marine species in Costa Rica is certainly far higher. In some groups the numbers are likely to be vastly higher because to date they have been so little studied. Only one species of nematode is reported, despite the fact that it has been said that nematodes are the most diverse of all marine groups. In better studied groups such as mollusks and crustaceans, reported numbers are in the thousands, but even in these groups many species remain to be described. Indeed the task of describing marine species is daunting – if there really are about 9 million marine species and Costa Rica has 3. 5% of them, then the total number would be over 300,000. Clearly, so much remains to be done that new approaches are needed. Genetic methods have en- mous promise in this regard.
Research whilst compiling this book has uncovered a fauna about twice the size as that previously published in the literature and consequently Systema Porifera revises and stabilizes the systematics of the phylum to accommodate this new knowledge in a contemporary framework. Practical tools (key illustrations, descriptions of character) are provided to facilitate the assignment of approximately 680 extant and 100 fossil genera. Systema Porifera is unique making sponge taxonomy widely available at the practical level of classification (genera, families, order). It is a taxonomic revision of sponges and spongiomorphis (such as sphinctozoans and archaeocyathans) based on re-evaluation of type materials and evidence. It is also a practical guide to sponge identification providing descriptions and illustrations of characters and interpretation of their importance to systematics. Systema Porifera addresses many long standing nomenclatural problems and provides a sound baseline for future debate on sponges and their place in time and space. Systema Porifera describes 3 classes, 7 subclasses, 24 orders, 127 families and 682 valid genera of extant sponges (with over 1600 nominal generic names and an additional 500 invalid names treated). Treatment of the fossil fauna is less comprehensive or critical, although 6 classes, 30 orders, 245 families and 998 fossil genera are mentioned. Keys to all recent and many fossil taxa are provided.
This landmark scientific reference for scientists, researchers, and students of marine biology tackles the monumental task of taking a complete biodiversity inventory of the Gulf of Mexico with full biotic and biogeographic information. Presenting a comprehensive summary of knowledge of Gulf biota through 2004, the book includes seventy-seven chapters, which list more than fifteen thousand species in thirty-eight phyla or divisions and were written by 138 authors from seventy-one institutions in fourteen countries. This first volume of Gulf of Mexico Origin, Waters, and Biota, a multivolumed set edited by John W. Tunnell Jr., Darryl L. Felder, and Sylvia A. Earle, provides information on each species' habitat, biology, and geographic range, along with full references and a narrative introduction to the group, which opens each chapter.
Although sponges are one of the major components of littoral ecosystems, their systematics obviously lags behind that of the majority of other groups of marine invertebrates. Also the evolutionary trends in these most primitive of the Metazoans are poorly understood. The confused state of their taxonomy and the difficulties with their identification prevent their use in ecological studies. The emphasis of interest presently seems to have shifted towards chemistry, but many of the hundreds of interesting chemicals recently described in sponges pro bably have been found in mistakenly or imprecisely identified animals. This situ ation will become worse in the next few years, when a number of experts will retire and will not be replaced by new ones, owing to the difficulties that the science of systematics is facing in most countries - as exemplified during this meeting by an informal discussion on the endangered future of European Museums. Under these circumstances, it is the responsability of present sponge taxono mists to leave a less confused state and tools such as simple fauna or computerized data bases to generations following. These tools do not exist even in one of the best studied areas, the North-Eastern Atlantic (including the Mediterranean Sea).
Numerous animal species live in environments characterized by a seasonal reduction in the availability of water, which often but not always occurs when temperatures are highest. For many such animals, survival during the toughest season requires spending long periods of time in a rather inactive state known as aestivation. But aestivation is much more than remaining inactive. Successful aestivation requires the selection of a proper microhabitat, variable degrees of metabolic arrest and responsiveness to external stimuli, the ability to sense the proper time of year for emergence, the preservation of inactive tissue, and much more. So, aestivation involves a complex collection of behaviors, ecological associations and physiological adjustments that vary across species in their type, magnitude and course. This book seeks to explore the phenomenon of aestivation from different perspectives and levels of organization, ranging from microhabitat selection to genetic control of physiological adjustments. It brings together authors from across the world working on different systematic groups, approaches, and questions, but who are all ultimately working to better understand the complex issue of aestivation.