Astacidae

Abstract: Horton H. Hobbs, Jr. An Illustrated Checklist of the American Crayfishes (Decapoda: Astacidae, Cambaridae, and Parastacidae). Smithsonian Contributions to Zoology, number 480, 236 pages, 379 figures, 1989.—This alphabetical list consists of the names of all of the American crayfishes, including two fossil species, that were described prior to 1 January 1988. In the treatment accorded each specific or subspecific taxon there is a synonymy citing alterations in generic and subgeneric assignments, erroneous spellings, and synonyms. References are also made to recent descriptions, discussions, and keys. The composition and locations of type series are cited, as are the type locality, range, and habitat of each. Nomina nuda that have been neither validated nor synonymized with other crayfish taxa, together with two names suppressed by the International Commission on Zoological Nomenclature, are listed separately. Comparable illustrations, which are arranged in related species groups, are presented for each of the 379 recognized extant species and subspecies. Appendix 1 provides an alphabetical list of American crayfishes and the countries, states, and/or provinces in which they live. Appendix 2 consists of an alphabetical list of American countries and states, or provinces, and their crayfish faunas; also cited are references to studies that pertain either directly to them or which should be helpful in studies of them. Appendix 3 includes information comparable to that in the main body of the checklist on crayfishes described during 1988 and 1989. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: The coral Montastrea cavernosa (Linnaeus). Library of Congress Cataloging in Publication Data Hobbs, Horton Holcombc, 1914An illustrated checklist of the American crayfishes (Decapods: Astacidae, Cambaridae, and Parastacidae). (Smithsonian contributions to zoology ; no. 480) Bibliography: p. Includes index. Supt. of Docs, no.: SI 1.27:480 1. Crayfish—United States. 2. Crustacea—United States. I. Title. II. Series QI1.S54 no. 480 591 s [595.3'841] 88-600418 [QL444.M33]

Abstract: Despite their widespread use as model organisms, the phylogenetic status of the around 520 species of freshwater crayfish is still in doubt. One hypothesis suggests two distinct origins of freshwater crayfish as indicated by their geographical distribution, with two centres of origin near the two present centres of diversity; one in south-eastern United States and the other in Victoria, Australia. An alternative theory proposes a single (monophyletic) origin of freshwater crayfish. Here we use over 3000 nucleotides from three different gene regions in estimating phylogenetic relationships among freshwater crayfish and related Crustacea. We show clear evidence for monophyly of freshwater crayfish and for the sister-group relationship between crayfish and clawed lobsters. Monophyly of the superfamilies Astacoidea and Parastacoidea is also supported. However, the monophyly of the family Cambaridae is questioned with the genus Cambaroides being associated with the Astacidae.

Abstract: Austropotamobius torrentium (SCHRANK, 1803) is the smallest of the European native crayfish species and has probably never been of economic interest. It is confined to headwaters and adapted to cold water with high flow through and rocky environments. These properties make the stone crayfish a useful species for population genetics and phylogeographic studies. Representatives were collected from 18 localities throughout southern Germany and analysed with two mitochondrial genetic markers. Initial results revealed that German populations of A. torrentium from the Danube and Rhine tributaries share identical haplotypes in 528 basepairs of 16S rRNA and 658 basepairs of the COI gene. Rare haplotypes of the COI genes were occasionally encountered and apparently restricted to southwestern Bavaria. Only three variable sites were found over a length of 658 basepairs in 45 German, Swiss and Austrian stone crayfish resulting in five different haplotypes, with the prevalence of one most common haplotype. Here we show that in German populations rare haplotypes are not randomly distributed, but found in higher frequencies in the Bavarian Alps of the Allgau and in adjacent Tyrol. On the other hand, stone crayfish population from the Bavarian Forest and the Rhine tributaries appear genetically impoverished, so far only showing the most common haplotype. Consequently, there are significant differences between the Allgau populations and the rest of the German populations in haplotype frequencies, resulting in a relatively high F ST value. This finding is of importance for future conservation efforts of stone crayfish populations in Germany and Austria.

Abstract: The author presents here the results of an introductory study into the setal armature of the British species of crayfish, Austropotamobius pallipes (Lereboullet, 1858). Using an ordinary optical microscope, it is demonstrated that a considerable variety of setae exist on the body and appendages of A. pallipes. These setae are described, and their distribution indicated. The setae fall into two main groups: (1) Setae with relatively thick walls and inconspicuous ampulla, and having no basal septum. (2) Those setae with relatively thin walls, a well-developed ampulla and basal septum. Further subdivisions of these two groups are made on the bases of outgrowths and outlines of the setal wall. Finally, the significance of the distribution and the variation, is discussed in relation to crayfish behaviour and function, linking the observed morphological facts with the results of some current electro-physiological experiments performed on related decapods.