THESES ZOOLOGICAE VOLUME 14 EDITOR: RONALD FRICKE Synopses of the Antarctic Benthos Volume 2 Editors: J. W. Wagele & J. Sieg Antarctic Isopoda Valvifera by J. W. Wagele «l KOENIGSTEIN KOELTZ SCIENTIFIC BOOKS 1991 Author's Address CONTENTS Johann-Wolfgang Wagele Fachbereich Biologie Introduction 9 Universitat Oldenburg Early studies on Antarctic Isopoda 10 Postfach 2503 Morphology and Glossary of Special Terms 13 D-2900 Oldenburg/Germany Morphology 13 Glossary _ ig Anatomy 13 Development and Reproduction 20 The Biology of Antarctic Isopoda 22 Collection, Preservation and Examination 33 Systematic Part 34 Classification of the Isopoda 34 Key to Suborders found in Antarctica 37 Suborder Valvifera 41 Key to the Families of the Suborder Valvifera 42 Family Chaetiliidae 43 Key to the Genera of Antarctic Chaetiliidae 43 Glyptonotus 43 Macrochiridotea 47 Family Idoteidae 51 Key to the Antarctic Genera of Idoteidae 51 Cleantis 52 Zenobianopsis 54 Edotia 57 Erichsonella 71 Idotea 73 Paridotea 75 Family Arcturidae 79 Key to the Subfamilies of Arcturidae 79 Subfamily Pseudidotheinae 80 Key to the Genera of Antarctic Pseudidotheinae 81 Arcturides 32 © Koeltz Scientific Books, D-6240 Konigstein/Germany Pseudidothea g4 ISBN 3-87429-324-6 Subfamily Arcturinae 88 Koeltz Scientific Books (USA), RR7, Box 39 Key to the Genera of Antarctic Arcturinae 88 Champaign, Illinois 61821, USA Neastacilla 91 ISBN 1-878762-18-4 Dolichiscus 98 ISSN 0934-8956 Paradolichiscus 112 Chaetarcturus 117 8.7.3.6. Tuberarcturus 126 FOREWORD 8.7.3.7. Litarcturus 130 8.7.3.8. Oxyarcturus 138 8.7.3.9. Antarcturus 144 8.7.3.10. Acantharcturus 168 The Synopses of the Antarctic Benthos are designed to meet the needs of 8.7.3.11. Mixarcturus 170 zoologists and naturalists interested in the Antarctic ecosystem. All 8.7.3.12. Fissarcturus 174 volumes are written by specialists in their own fields. It was intended to 8.7.3.13. Cylindrarcturus 180 publish all the information needed for the identification of species leav­ 8.7.3.14. Neoarcturus 182 ing out data which are of interest only for specialized taxonomists. If you 8.7.3.15. Rectarcturus 192 find specimens you cannot identify with the help of these volumes, your 9. Acknowledgements 194 material may belong to new species, which should be described carefully 10. References 195 and as completely as possible. Please send this material to a specialist. 11. Index 207 The series will not be complete because of two reasons: The Southern Ocean has until today many unexplored areas, in future many new species will be described which were not known to our authors; for some tax- onomic groups no specialists could be found. Nevertheless we hope that the volumes will help all those working with Antarctic benthos and that the efforts of the taxonomists who have given their knowledge, time and services to write a monograph will be used for the description and protec­ tion of one of the most untouched ecosystems of our planet. J.W. Wagele, J. Sieg (Editors) 1. INTRODUCTION The Amphipoda and the Isopoda are the most frequent crustaceans found in benthic environments of Antarctica. These groups are also an important element of the sea floor fauna in temperate and tropical seas, but there the largest crustaceans are always the Decapoda. It seems that in Antarctica most of the decapod crustaceans disappeared in the course of the climatic changes that led to the glaciation of the southern continent. The life cycle, especially the larval development of most Decapoda could probably not be adapted to the short phytoplankton blooms and the low temperatures that slow down the metabolism. Antarctic invertebrate faunas have a high percentage of species with lecitotrophic larvae or direct development and brooding (Arnaud 1977, Dell 1972, Magniez 1983, Pearse et al. 1985, Picken 1979, 1980). This might be the reason for the success of the higher evolved Peracarida, who are entirely brooders. The isopods considered in this monograph are those known from the area between the Antarctic convergence, the Subantarctic archipelagos and the littoral of the Antarctic continent, including the deep sea of the Southern Ocean. Several of the species mentioned in this series are still poorly known; it is no secret that sometaxonomic publications of the past do not allow a clear determination of species, that several published drawings are not very useful. To prepare this monograph a series of taxonomic studies were carried out and published elsewhere, based on material from expedi­ tions of RV "Polarstern" to the Atlantic sector of the Southern Ocean and on collections kept in different museums. Nevertheless, much work still remains to be done and still many species are waiting for their discovery and scientific study. 10 11 2. EARLY STUDIES ON ANTARCTIC Borchgrevink, with the first wintering shore party on the continent at Cape Adare, yielded a first collection of 9 high-Antarctic species, most of ISOPODA them from Cape Adare, described by Hodgson (1902). An important contribution to our knowledge of the Antarctic fauna was based on the material of the "Challenger" expedition, led by C.W. Thom­ Early in the nineteenth century, when the southern borders of the circum- son to the area around Marion and Heard Island and the Kerguelen polar ocean were known, the most interesting elements of the Antarctic Islands between December 1873 and February 1874. The isopods were fauna seemed to be the whales, while only few scientists started to collect studied by Beddard, who published in 1884 beautiful plates of species of plants and invertebrates. One of these scientists was James Eights, who Serolis and in 1886 descriptions and excellent drawings of the remaining was "the first qualified naturalist to set foot on land south of the Antarc­ taxa. Though the descriptions were not as' complete as those of the tic Convergence" (Hedgpeth 1971). He took part in Captain E. Fanning's famous Norwegian zoologist G.O. Sars, the standard of these drawings expedition to South America and Antarctica in 1829-1831 and collected a was not reached by many of the scientists who published in the twentieth large number of natural history specimens, among these the first Antarc­ century. A first comprehensive study of the crustaceans of South Georgia tic isopods. His description of "Brongniartia" trilobitoides from the was prepared by Pfeffer (1887, 1890). Here we find the names of some shores of the South Shetland Islands was published in 1833. Eights was species, which are common in more southern areas, as 'Chelonidium' puzzled by the similarity with the extinct trilobites, but correctly placed (Plakarthrium) punctatissimum and Glyptonotus antarcticus, as well as his new species in the Crustacea Malacostraca. As we know today, this other species, which do not reach farther south (Sphaeromatidae). similarity is a consequence of the adaptations to life on sandy bottoms which are characteristic for the Serolidae (Wagele, 1989). In a note During the German Deep-Sea Expedition (1898-1899) with the "Valdivia", published in 1852 Eights suspected that his species was possibly a Serolis. a former Hamburg-America liner, four arcturids were obtained and later It is the largest species of its family known until today. The same is true studied by zur Strassen (1902). Zur Strassen erected the new genus Antarc- for Glyptonotus antarcticus (Family Chaetiliidae), "... a New Animal turus for the southern arcturids and described A. oryx from off Bouvet belonging to the Crustacea, discovered in the Antarctic Seas, by the Island. author James Eights" (1852), also from the shores of the South Shetlands. The first remarkable collection from high Antarctic sites was obtained Some smaller publications followed. Dana for example described in 1852 during R. Scott's "Discovery" expedition, which led into the Ross Sea Cleantis linearis, Chaetilia ovata (Valvifera) and Exosphaeroma gigas (1902). TV. Hodgson collected and described (1910) 23 species, most of from Patagonia, collected during Charles Wilkes' U.S. Exploring Expedi­ them illustrated in 10 fine plates. The material from the German South tion, while during the Antarctic cruises no new isopods were taken. A Polar Expedition (1901-1903) under E. von Drygalski with the "Gauss", Patagonian Serolis was named after the governor of Punta Arenas S. which was frozen in the ice close to the continent (66°2'9"S 89°38'5"E) is schythei by Liitken (1858). Studer (1879, 1882) studied the material col­ of comparable importance, but VanhOffen's drawings are of poorer lected by the German 'Gazelle* expedition (1874-1876), described Serolis quality (Vanhoffen 1914). cornuta (now Ceratoserolis) and S. ovalis, Arcturus furcatus (now Antarc- turus) and the interesting new genus Arcturides (for A. cornutus n.sp.), all Jean Charcot's first expedition with the "Francais" (1903-1905) also car­ from Kerguelen. Studer (1882) realized that Arcturides was mor­ ried out biological programmes. The small collection of isopods was phologically a link between the Idoteidae and the specialized Arcturus. described by Miss H. Richardson (1906, 1908), who was busy studying Further subantarctic collections were studied by Miers, among these isopods from all over the world. Richardson's drawings were not better materials brought back from Kerguelen by officers of the Antarctic than VanhOffen's, redescriptions for many of these species are necessary. expedition of James Ross, who visited the island in May and June 1840 The last of the more famous names from the heroic era of the scientific (Miers 1879). The "Southern Cross" expedition of 1898-1900 led by C.E. exploration of Antarctica is Tattersall. He had prepared a study (Tattersall 12 13 1914) on the non-Antarctic Isopoda from the Scottish National Antarctic Expedition (1902-1904), the Antarctic 'ScotiaJ-material was in hands of 3. MORPHOLOGY AND GLOSSARY Hodgson. Tattersall received the material from R. Scott's ill-fated "Terra OF SPECIAL TERMS Nova" expedition (1910-1913), which contained among others 26 "truly Antarctic" species (Tattersall 1921).