The Echinogammarus Berilloni-Group, a Number of Predominantly Iberian Amphipod Species (Crustacea)
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The Echinogammarus berilloni-group, a number of predominantly Iberian Amphipod species (Crustacea) by Sjouk Pinkster Institute of Taxonomie Zoology, University of Amsterdam, The Netherlands Abstract INTRODUCTION The morphological diversity within the species Echino- the last 10 15 of staff- During or years a group gammarus berilloni (Catta, 1878), stressed by Spandl members and students the Instituut (1926), Margalef (1956) and Pinkster (1969) was a motive at voor in of the to sample systematically drainage systems Taxonomische Zoölogie of the University of Am- Iberian peninsula and of great parts of France. It became sterdam, coached by the enthusiasm of Prof. Dr. clear that E. berilloni in reality was the collective name J. H. has been on both for of least 10 all of them with their Stock, working systemati- a group at species, cal and ecological problems of fresh and brackish own, restricted distribution area. Only one of these species, the real E. berilloni, inhabits a much larger area, water As member of this amphipods. a young including the major part of France, the Channel islands, team, I collected some gammarids in the western Belgium, Luxembourg, the southern part of the Nether- Pyrenees in 1968. While studying this material it lands, and south-western Germany. In this study the became clear, that E. berilloni (Catta) was not characters of the E. berilloni-group are discussed and variable comparative descriptions are given of all species, along only a very species, as already noticed by with a key for their identification. The variability and Spandl (1926) and Margalef (1956), but in reality ecological preferences of each species are discussed. a collective name for a group of closely related An attempt has been made to relate the distribution species, each variable in itself. This resulted in the of this and of other in the pattern group species groups description of a new E. aquilifer Pinkster, Iberian peninsula (e.g. the E. simoni-group, members of species, the G. and the and likewise it the start for pulex-group, genus Eulimnogammarus) to 1969, was a more geological data. intensive study of the subject. One of the fertile methods solve most to system- Résumé atic when of problems, especially a group variable is is La variabilité morphologique de l’espèce Echinogam- species involved, to sample syiemati- and in the inhabited marus berilloni (Catta), remarquée par Spandl (1926), caJly intensively area by the Margalef (1956) et Pinkster (1969) a mené à un échantil- group in question. In doing so variability withinand lonnage systématique dans les systèmes d’eaux de la between various populations of one species, as well dans la France. Il Péninsule ibérique et presque toute a as differences become clear. E. berilloni était réalité le nom collectif interspecific may été prouvé que en d’au moins 10 dont chacune a has been done, pour un groupe espèces, Consequently systematic sampling son aire de distribution limitée. Il n’y a qu’une seule de in the years 1969, 1970 and 1971, in all drainage le vrai E. aire beau- ces espèces, berilloni, qui occupe une of the Iberian systems peninsula (see map I) and la de coup plus étendue, comprenant plus grande partie in many parts of France (Pinkster et al., 1970; la France, les îles de la Manche, la Belgique, Luxem- Pinkster & Stock, bourg, la partie méridionale des Pays-Bas, et la partie 1971). Since sud-ouest de l’Allemagne. morphological characters are changing cette note les caractères des Echinogammarus du Dans during the development, and consequently, various berilloni discutés des com- groupe sont et descriptions stages of different species often are very much paratives de toutes les espèces sont données, ainsi qu’une alike (see Dennert et al., 1969), sexually mature clef de détermination. En outre la variabilité et les pré- be used In obtain férences écologiques de chaque espèce sont indiquées. specimens can only. order to modèle de distribution du Enfin l’auteur propose un more information about the ecology of the dif- des de la Péninsule groupe et autres groupes d’espèces ferent members the of group, analyses of water le les membres du ibérique (p. ex. groupe E. simoni, samples were made at nearly every station for the G. ex et le Eulimnogammarus) par rap- groupe pul genre factors temperature, pH, chlorinity and calcium port aux données géologiques. Downloaded from Brill.com10/08/2021 03:18:23PM via free access 2 S. PINKSTER - THEECHINOGAMMARUS BERILLONI-GROUP ion concentration. Moreover, the width and depth tion to the authorities in their countries. The author is much indebted to Prof. Dr. J. H. Stock of the of the streams inhabited, bottom type, vegetation, Institute of Taxonomie Zoology (Zoölogisch Museum), Amster- and degree of pollution were noted. dam (ZMA) for his kind assistance during part of the As a result of this systematic inventarisation, it fieldwork and for his critical remarks during all phases became clear that the name E. berilloni, as used of the work. to in up 1969 (see Pinkster, 1969), reality is the collective noun for a group of at least 10 closely THE CHARACTERS OF THE ECHINOGAM- related, but distinct forms. Nine of these species MARUS BERILLONI-GROUP are restricted to rather small areas in the northern half of the Iberian of Stock and Pinkster Stock peninsula or the adjacent part (1968) & (1972) sum- France. Only one species, E. berilloni s.str. has a marized the most important characters discrimi- the much wider distribution, inhabiting the middle nating Echinogammarus pungens-group and reaches of streams and rivers in France, the Chan- the E. simoni-group from other representatives nel Islands, Belgium, Luxembourg, the southern within the genus Echinogammarus. In this paper treated which part of the Netherlands and south-western Ger- species are are all closely related to, or confused with, berilloni many. In Spain the species seems to be restricted Echinogammarus (Cat- rather and defined the to a narrow zone along the north-west ta), are by following characters: coast. (1) the eyes are large and elongate; (2) the hands of the In spite of our intensive sampling, no members first gnathopods are much smaller than of those of the all armed with the E. berilloni-group were found in the second; (3) legs are of sometimes southern part of the Iberian peninsula. In this area groups setae, accompanied by some smaller they seem to be completely replaced by members spines; (4) the carpus of the second leg is of the African E. simoni-group (Pinkster & Stock, always much shorter than the propodus; (5) the 1972). segments of both metasome and urosome are In this of armed with and often paper complete descriptions all mem- spines groups of, very long, bers of for their calceoli the first the E. berilloni-group and a key setae; (6) are always absent; (7) of the mandible is identification are given. The distribution of the segment palp always unarmed, the third bears comb- various species is discussed and illustrated in maps, segment always a regular and where possible, notes are given on the varia- like row of setae. These characters also occur in and the of the different the females, although less pronounced than in the bility ecological range males. in E. calvus species. In a final chapter, the distribution of all Although some species (e.g. and E. characters and less groups of amphipods inhabiting inland waters in echinosetosus) (3) (5) are the Iberian and than in most other members of this peninsula its zoogeographical as- pronounced and tend to become intermediate between pects are discussed. group this group and the Echinogammarus pungens- ACKNOWLEDGEMENTS group, I still believe, after weighing the various characters against each other that the members of The author is indebted to Dr. R. Margalef of the Instituto the E. berilloni-group can be distinguished from de Investigaciones Pesqueras for the loan of type material the other within the Echino- of Echinogammarus klaptoczi ebusitanus; also for the species-groups genus loan of of the material to Dr. R. W. Ingle British Mu- gammarus. seum (Natural History) (BMNH), London; to Dr. L. B. Considering the characters cited above, Echino- Holthuis of the Rijksmuseum van Natuurlijke Historie & Ruffo, gammarus pacaudi (Hubault 1956) (RMNH), Leiden; to Dr. S. Ruffo of the Museo Civico but should be placed within this group of species, di Storia naturale (MCSN), Verona; and to Dr. J. Nies- the dorsal ornamentation of the metasome, very sen, of the Zoologisch Museum Utrecht (ZMU). To Mrs. I. Pinkster-de Graaf and Miss A. M. C. Goedmakers, B. characteristic by its sharp, teeth-like projections, Sc., for their assistance during part of the fieldwork; to other makes this species so different from all Mr. R. Dijkema, B. Sc., for drawing the map with the that I species within the genus Echinogammarus drainage systems; to Dr. O. J. Simons, of the Geologisch it When to as a group. Instituut of the University of Amsterdam, for his advice prefer separate special of E. ebusitanus in geological problems. reading the description klaptoczi The fieldwork was made of the whether this possible through grants Margalef, 1951, one hesitates as to Netherlands' Organisation for the Advancement of Pure form should be placed within the E. berilloni- Research (Z.W.O.) and of the University of Amsterdam. Examination of the material group or not. type Special thanks are also due to the Embassies of Spain the to this The taxon and Portugal in the Netherlands for their kind introduc- provided answer problem. Downloaded from Brill.com10/08/2021 03:18:23PM via free access BIJDRAGEN TOT DE DIERKUNDE, 43 (1) - 1973 3 ebusitanus cannot be included in the berilloni- urosome segments.