Three major aspects that distinguish this book are that (1) it contains the most detailed analysis of the sexual reproduction (oogenesis, fertilization and embryonic incubation) in a particular phylum of the aquatic invertebrates (Bryozoa) ever made; this analysis is based on an exhaustive review of the literature on that topic published over the last 260 years, as well as extensive original histological, anatomical and morphological data obtained during studies of both extant and extinct species; (2) this broad analysis has made it possible to reconstruct the major patterns, stages and trends in the evolution of sexual reproduction in various bryozoan clades, showing numerous examples of parallelisms during transitions from broadcasting to embryonic incubation, from planktotrophic to non-feeding larvae and from lecithotrophy to placentation; corresponding shifts in oogenesis, fertilization and embryonic development are discussed in detail; and (3) the key evolutionary novelties acquired by Bryozoa are compared with similar innovations that have evolved in other groups of marine invertebrates, showing the general trends in the evolution of their sexual reproduction. Ecological background of these innovations is considered too. Altogether these aspects make the monograph an “Encyclopedia of bryozoan sexual reproduction,” offering an integral picture of the evolution of this complex phenomenon.

This reference work is designed to provide background information on an array of northeastern Pacific marine invertebrate species so that they can be more easily included in comparative studies of morphology, cell biology, reproduction, embryology, larval biology, and ecology. It is meant to serve biologists who are new to the field as well as experienced investigators who may not be familiar with the invertebrate fauna of the northern Pacific Coast. The species discussed in this volume are mostly from the cold temperate waters of the San Juan Archipelago, near Puget SOund and the Strait of Georgia, but the information and methods given will be useful in laboratories from Alaska to central California and applicable to some extend in other coastal or inland facilities. An introductory chapter discusses basic prodcedures for collecting and maintaining mature specimens, for initiating spawning, and for culturing embryos and larvae in the laboratory. Subsequent chapters summarize reproduction and development in thirty different invertebrate groups and provided ercent references through which additional information can be traced, cite monographs or keys needed to identify species, and give methods useful for studying an array of selected species. Available information on habitat, diet, reproductive mode, egg size, developmental pattern, developmental times, larval type, and conditions for settlement and metamorphosis is reported for over 450 species.

"More than seventy percent of the earth's surface is covered by the ocean which is home to a staggering and sometimes overwhelming diversity of organisms, the majority of which reside in pelagic form. Marine invertebrate larvae are an integral component of this pelagic diversity and have stimulated the curiosity of researchers for centuries. This accessible, upper-level text provides an important and timely update on the topic of larval evolution and ecology, representing the first major synthesis of this interdisciplinary field for more than 20 years. The content is structured around four major areas: evolutionary origins and transitions in developmental mode; functional morphology and ecology of larval forms; larval transport, settlement, and metamorphosis; larval ecology in extreme and changing environments. This novel synthesis integrates traditional larval ecology with life history theory, evolutionary developmental biology, and modern genomics research to provide a research and teaching tool for decades to come." -- from the rear cover.

Echinoderms and prochordates occupy a key position in vertebrate evolution. The genomes of sea urchin share 70% homology with humans. Researches on cell cycle in sea urchin and phagocytosis in asteroids have fetched Nobel Prizes. In this context, this book assumes immense importance. Echinoderms are unique, as their symmetry is bilateral in larvae but pentamerous radial in adults. The latter has eliminated the development of an anterior head and bilateral appendages. Further, the obligate need to face the substratum for locomotion and acquisition of food has eliminated their planktonic and nektonic existence. Egg size, a decisive factor in recruitment, increases with decreasing depths up to 2,000-5,000 m in lecithotrophic asteroids and ophiuroids but remains constant in their planktotrophics. Smaller ( 110 mm) asteroids generate planktotrophic eggs only. Publications on sex ratio of echinoderms indicate the genetic determination of sex at fertilization but those on hybridization, karyotype and ploidy induction do not provide evidence for heterogametism. But the herbivorous echinoids and larvacea with their gonads harboring both germ cells and Nutritive Phagocytes (NPs) have economized the transportation and hormonal costs on gonadal function. Despite the amazing potential just 2 and 3% of echinoderms undergo clonal reproduction and regeneration, respectively. Fission is triggered, when adequate reserve nutrients are accumulated. It is the most prevalent mode of clonal reproduction in holothuroids, asteroids and ophiuroids. However, budding is a more prevalent mode of clonal reproduction in colonial hemichordates and urochordates. In echinoderms, fission and budding eliminate each other. Similarly, autoregulation of early development eliminates clonal reproduction in echinoids and solitary urochordates. In pterobranchs, thaliaceans and ascidians, the repeated and rapid budding leads to colonial formation. Coloniality imposes reductions in species number and body size, generation time and life span, gonad number and fecundity as well as switching from gonochorism to simultaneous hermaphorditism and oviparity to ovoviviparity/viviparity.

In Reproduction and Development of Marine Invertebrates a group of internationally recognized researchers assesses the state of current knowledge in the field and identifies future avenues of research. Comprehensive in scope, the book treats all levels of biological organization, from the molecular level to communities of organisms. After a brief historical overview that identifies the conceptual underpinnings of twentieth-century invertebrate zoology and embryology, the book is organized by developmental stages. The authors first present chapters on oogenesis, spermatogenesis, fertilization, and embryonic development. A subsequent section--arranged phylogenetically to encompass annelids, priapulans, molluscs, bryozoans, and echinoderms--covers larval morphology and evolution. The final section treats larval or adult populations and includes new information on the role of hydrodynamics to aid in the understanding of larval dispersal and settlement. Reproduction and Development of Marine Invertebrates is the first book of its kind to be published since 1978. Extensivelyillustrated with more than a hundred line drawings and photos--including sixty high-resolution electron micrographs--it will be of interest to professionals and students in evolutionary biology, invertebrate zoology, developmental biology, and functional morphology.

This is the first book to provide a detailed treatment of the field of larval ecology. The 13 chapters use state-of-the-art reviews and critiques of nearly all of the major topics in this diverse and rapidly growing field. Topics include: patterns of larval diversity, reproductive energetics, spawning ecology, life history theory, larval feeding and nutrition, larval mortality, behavior and locomotion, larval transport, dispersal, population genetics, recruitment dynamics and larval evolution. Written by the leading new scientists in the field, chapters define the current state of larval ecology and outline the important questions for future research.

Reproduction of Marine Invertebrates, Volume I: Acoelomate and Pseudocoelomate Metazoans is a collection of papers that deals with the evolution of reproductive mechanisms and behavior in marine invertebrates. This collection starts with terminologies and basic events in marine invertebrate reproduction, including the method of estimating sexual reproductive activity, as well as the timing and patterns involved. The book notes that temperatures, salinities, or food availability should be favorable when the young are produced and when they are developing. One paper shows that the reproductive rhythm is dynamic and in some species is latitude-dependent. Other papers discuss the reproductive cycles of different marine invertebrates such as the Porifera, Cnidaria, Nemertinea, and Nematoda. These papers include topics on asexual reproduction, regeneration, sexual reproduction, and development, and then explain in detail the development of certain invertebrates from their kinorhynchs state (embryonic), to the molting stages, juvenile stages, then to adulthood. This book can be useful for marine biologists, marine ecologists, and students involved in marine biological and physical sciences.

This reference work is designed to provide background information on an array of northeastern Pacific marine invertebrate species so that they can be more easily included in comparative studies of morphology, cell biology, reproduction, embryology, larval biology, and ecology. It is meant to serve biologists who are new to the field as well as experienced investigators who may not be familiar with the invertebrate fauna of the northern Pacific Coast. The species discussed in this volume are mostly from the cold temperate waters of the San Juan Archipelago, near Puget SOund and the Strait of Georgia, but the information and methods given will be useful in laboratories from Alaska to central California and applicable to some extend in other coastal or inland facilities. An introductory chapter discusses basic prodcedures for collecting and maintaining mature specimens, for initiating spawning, and for culturing embryos and larvae in the laboratory. Subsequent chapters summarize reproduction and development in thirty different invertebrate groups and provided ercent references through which additional information can be traced, cite monographs or keys needed to identify species, and give methods useful for studying an array of selected species. Available information on habitat, diet, reproductive mode, egg size, developmental pattern, developmental times, larval type, and conditions for settlement and metamorphosis is reported for over 450 species.

This book is a concise informative elucidation of all aspects of reproduction and development in annelids covering from arenicola to tubifex. Annelids flourish between 4,900 m depth to 2,000 m altitude; some of them occur in unusual habitats like hydrothermal vents and subterranean aquatic system (stigobionts). A few have no gut and acquire adequate nutrients through osmotrophism and/or engaging symbiotic microbes. In the absence of exoskeleton to escape predation, the 17,000 speciose annelids have explored bewildering modes of reproduction; not surprisingly, 42–47% of them are brooders. With 13,000 species, polychaetes are gonochores but some 207 species of them are hermaphrodites. Clitellates are all hermaphrodites; of them, 76 species are parthenogens, of which 56 are earthworms. Regenerative potency of annelids ranges from an organ to an entire worm from a single ‘seminal’ segment. The head, tail and both together can be regenerated 21, 42 and 20 times, respectively. However, the potency is limited to ~1% of polychaetes and Heterogamatic sex determination is reported to occur only in six polychaete species, although karyotype is known for 83 annelid species. In temperate polychaetes, a dozen neuroendocrines, arising mostly from the ‘brain’ regulates reproductive cycle. A complete chapter devoted to vermiculture, (i) recognizes the fast-growing candidate species, (ii) distinguishes 'layers' from 'brooders', (iii) indicates that the harvest of oligochaetes may reduce the input of nitrogenous fertilizer in the ricefield, and (iv) explores the scope for increasing wealth from waste.