Crustaceans, due to the great diversity of their body organization, segmentation patterns, tagmatization, limb types, larval forms, cleavage, and gastrulation modes, are highly desirable for the study of questions at the interface of evolution and development. Modern interest in evolutionary developmental biology (evo-devo) rests on the molecular genetic approach and a variety of molecular techniques have proven fruitful when performed on crustaceans. Evolutionary Developmental Biology of Crustacea presents a comprehensive treatment of all aspects of the field, beginning with a discussion of the implications of the typological Bauplan and phylum concepts versus historical concepts such as ground pattern and monophylum for the formulation of conceptual questions in evo-devo. Following this, the authors present the results of Hox gene expression in various crustacean taxa, aspects of segment formation at the cellular and genetic levels, the formation of segmental structures such as neurons, ganglia, and limbs, and the role of morphological ontogenetic characters in resolving phylogenetic relationships. By covering so many general aspects of crustacean development, morphology, and evolution, Evolutionary Developmental Biology of Crustacea serves as an indispensable reference for developmental and evolutionary biologists investigating the role of genetics in evolution and development.

Thorp and Covich's Freshwater Invertebrates: Keys to Palaearctic Fauna, Fourth Edition, is part of a multivolume series covering inland water invertebrates of the world that began with Vol. I: Ecology and General Biology (2015), then Vol. II (2016) Keys to Nearctic Fauna, and finally in Vol. III (2018) Keys to Neotropical Hexapoda (insects and springtails). It now continues with identification keys for Palearctic invertebrates in Vol. IV. Two other volumes currently in development focus on general invertebrates of the Neotropical/Antarctic, and Australasian Bioregions. Other volumes in the early planning stages include Afrotropical and Oriental/Oceanic Bioregions. All volumes are designed for multiple uses and levels of expertise by professionals in universities, government agencies and private companies, as well as by graduate and undergraduate students. - Provides identification keys for inland water (fresh to saline) invertebrates of the Palearctic Zoogeographic Region, from Iceland to Russia, and from the northern Pole region to Saharan Africa in the west, through the Middle East, and to the central China and Japan in the east - Presents identification keys for aquatic invertebrates to the genus or species level for many groups and to family for Hexapoda, with the keys progressing from higher to lower taxonomic levels - Includes a general introduction and sections on limitations, terminology and morphology, material preparation and preservation and references

As evident from the number 4A tagged to this volume, vol. 4 as originally planned had to be split into two fascicles, 4A and 4B, simply because of the numbers of pages covered by the various contributions meant for volume 4. The present volume, then, comprises the fourth part in the series The Crustacea, i.e., the revised and updated texts from the Traité de Zoologie – Crustacea. The chapters in this book grew out of those in the French edition volume 7(II). The exception is chapter 49, which has been newly conceived; it was never published in French. Overall, this constitutes the sixth tome published in this English series, viz., preceded by volumes 1 (2004), 2 (2006), 9A (2010), 9B (2012), and 3 (2012). Readers/users should note that we have had to abandon publishing the chapters in the serial sequence as originally conceived by the late Prof. J. Forest, because the various contributions, i.e., both the updates and the entirely new chapters, have become available in a more or less random order. This fourth volume, part A, of The Crustacea contains chapters on: • Genetic variability in Crustacea • Class Cephalocarida • Class Remipedia • Subclass Hoplocarida: order Stomatopoda • Superorder Syncarida

Crustacean preparations have been successfully used for more than 50 years to investigate the principles which enable nerve cells and neural circuitry to perform in a wide variety of functions. The proud record of information of general significance obtained from crayfish and lobster nervous systems testifies that the use of an experimental system precisely matching theoretical and experimental requirements ofa measurement is an essential part of the success. In some respects, the secondarily diversified vertebrate and mammalian nervous systems pose severe obstacles to experimentation and measurement, whereas the crustacean nervous system recommends itself by being composed of individual neurons of unique morphology and physiology, which can be used repeatedly in several preparations. Moreover, a restricted number of invariantly displayed behaviors enable the experimenter to correlate neuron activity with parts of the behavior easier. Experts use these advantages to focus on a well-defined neuron and mechanism and to take a convincing measurement within a minimum amount oftime. In this book distinguished neurobiologists, the leading experts in the field, have joined efforts to present research using crustacean experimental systems. Thus they have contributed comprehensive information regarding a nervous system other than that ofvertebrates and mammalians, that ofcrustaceans. The accumulated knowledge on the crustacean nervous system shows that it is clearly divergent in evolution but functions in a similar way to neuronal circuitry found in the vertebrate system and can be used to interpret it.

The scientific understanding of arthropod phylogeny and evolution has changed significantly in recent decades. One of the most momentous alterations involved crustaceans, which are not a monophyletc group, but are part of a larger group along with insects: Pancrustacea. The old ideas surrounding crustacean evolution have served scientists well for many years; it is now time to turn toward new research by embracing the results derived from investigations conducted largely within this century. For example, new definitions have arisen from sources across several fields of study, and Frederick R. Schram and Stefan Koenemann have created a book that explores paleobiodiversity and the diversity of modern body plans. Developments within ontogenetic studies continue to generate remarkable insights into crustaceomorph evolution in regard to patterns of embryology and a revolution in the application of development genetics. Phylogeny techniques of analysis and new sources of data derived from molecular sequencing and genetic studies have forced scientists to consider new hypotheses concerning the interrelationships of all the pancrustaceans, both the crustaceomorphs and Hexapoda. Yet, some fossil groups still remain enigmatic (Thylacocephala). Despite this, research into fossils (even if incompletely understood) fills in gaps of our knowledge of paleobiodiversity, and it's useful for many things, including analyzing the origin and early evolution of Hexapoda. Evolution and Phylogeny of Pancrustacea demonstrates the use of multiple alternative hypotheses and other techniques through the well-executed presentation of diverse data sources involving Pancrustacea. Readers are left with clues to great mysteries, including the possible pathways of evolution within marine arthropods.

Compared to other arthropods, crustaceans are characterized by an unparalleled disparity of body plans. Traditionally, the specialization of arthropod segments and appendages into distinct body regions has served as a convenient basis for higher classification; however, many relationships within the phylum Arthropoda still remain controversial.