L. Forró - É. Murai szerk.: Miscellanea Zoologica Hungarica 5. 1989 (Budapest, 1989)

Stoch, F.: Critical remarks on the southern Italian asellids described by E. Dudich (1925) with redescriptions of some taxa (Crustacea, Isopoda, Asellota)

ed in southern Italy. In the descriptive part of this work the essential synonymy (referred to only those papers in which systematic consideration on Italian taxa are given) and the material examined is listed. A redescription of the most important taxa or a short diagnosis, as well as some taxonomic remarks, are also given. DESCRIPTIVE PART Aselius aquaticus aquaticus ^L.i sensu Racovitza, 1919 Material examined: Lago Maggiore (northern Italy), leg. COLLIN, 2 males (HNHM 1626, determined by DUDICH as Asellus arthrobranchialis). Asellus aquaticus arthr

obranchi

alis Dudich, 192 5 Essential synonymy: Asellus arthrobranchialis Dudich, 1925a: 281; A. aquaticus arthrobranchialis: ARCANGELI 1942: p. 177; KARAMAN 1952: p. 68; SKET 1965: p. 185; A^ (s. str.) aquaticus : BIRSTEIN 1964: p. 54. Material examined: Sarno river, spring (original label: Sarno, sötét forrás), leg. E. DUDICH, 23. III. 1925, 10 males (HNHM 1630), 18 females (HNHM 1627L both labelled as type material (syntypes); Sarno river and its inflows (original label: Sarno, a Sarno és mellékvizeiben, cotypil, leg. E. DUDICH, 23. III. 1925, 6 specimens (HNHM 1629); Caserta, leg. E. DUDICH, 5. IX. 1925, 2 females and 1 damaged specimen (HNHM 1628). Sarno river, leg. KESSELYÁK, 28. V. 1930, 1 male (HNHM 1651L Type material: the specimens with the label "Typi" and "Cotypi" from Sarno river have to be considered as syntypes. Considering that the validity of this subspecies is still doubtful, and could be confirmed only with further researches on the populations from central and southern Italy. I have not fixed the lectotype. The type-material is deposited in the collections of the Zoological Department of the Hungarian Natural History Museum in Budapest. Diagnosis: Asellus aquaticus arthrobranchialis differs from type form in the small size of respiratory area on exopods of pleopods IV and V (see DUDICH, 192 5a; Figs 3-6). The description given by DUDICH (1925) is good. Remarks: A. aquaticus is a widely distributed species; its morphological variability and the enormous amount of material which should be re-examined for a complete revision of all its subspecies prevented me from presenting a correct interpretation of the Italian taxa in this paper. The most important question concerns the taxonomic position of ssp. arthrobranchialis (Dudich, 1925). Although the discriminating character used by DUDICH (presence of linea articularis in exopod of pleopods IV and V) cannot be considered as diagnostic (being common to A. aquaticus : KARAMAN, 1952), the size of respiratory area of the same appendages indicates that the population from Sarno River and the type form are, distinct (see KARAMAN 1952, 1952a). However, the degree of variation of this character important in the diagnosis of the taxa from Southeastern Europe (SKET 19651 - in the Italian populations is unknown. That is why I consider here arthrobranchialis as a doubtful, endemic subspecies of A. aquaticus. Several authors followed DUDICH in considering ssp. arthrobranchialis as a good species, and attributed some other European populations to this taxon. Obviously these diagnoses were wrong (see SKET 1965). Limiting the examples to Italy and neighbouring localities, I have observed that the specimens from Lake Maggiore (SCHMÖLZER 19 55) are closely related to the other populations from Northern Italy, well described by MORREALE (1924). I have examined several samples of them deposited in the collection of ARCANGELI. They belong to the type-form. A. aquaticus arthrobranchialis f. balcanica Karaman, 1 9 52 is probably a gr"oup of populations, which (following the opinion of SKET (1965) should be attributed partly to the type form and partly to a distinct subspecies (ssp. balcanicus

) (see also SKET 1965). A. aquaticus arthrpbranchialis f. cresana Karaman, 19 52 does not belong to this subspecies (SKET 1965, considered it as synonymous with the type form).