Ann. Limnol. 37 (4) 2001 : 281-292 A new genus and species of the family Ectinosomatidae (Crustacea : Copepoda : Harpacticoida) from the groundwaters of India T. Karanovic1 G.L. Pesce2 Keywords : Copepoda, Ectinosomatidae, Rangabradya, India, taxonomy. Rangabradya n. gen. and Rangabradya indica n. sp. from the subterranean freshwaters of India axe described. The new genus belongs to a group of genera in the family Ectinosomatidae Sars, 1904 possessing fusiform body shape and it is very similar to the genus Halectinosoma Lang, 1944. The new genus has the exopodite and basiendopodite of the fifth leg completely fused, without surface seta, as well as a characteristic appearance of the antennula, antenna and maxilla. The position of the genus Rangabradya n.gen. within the family Ectinosomatidae is discussed. Un nouveau genre de la famille Ectinosomatidae (Crustacea : Copepoda : Harpacticoida) des eaux souterraines de l'Inde Mots-clés : Copepoda, Ectinosomatidae, Rangabradya, Inde, taxonomie. Rangabradya n. gen. et Rangabradya indica n.sp. trouvés dans les eaux douces souterraines de l'Inde sont décrits. Le nou­ veau genre appartient au groupe des genres de la famille des Ectinosomatidae Sars, 1904 qui,ont un corps fusiforme et iLest tirés, proche du genre Halectinosoma Lang, 1944. Le nouveau genre possède les exopodite et baséôendbpddite de la cmquième patte, complètement soudés et dépourvus de soie accessoire. Les antennules, antennes et maxilles sont très caractéristiques. La posi-* tion du genre Rangabradya n. gen. dans la famille Ectinosomatidae est discutée. 1. Introduction 1924 ; Ectinosoma Boeck, 1865 ; Halectinosoma Lang, 1944 ; Halophytophilus Brian, 1917 ; Hastige- The family Ectinosomidae was established by Sars rella Nicholls, 1935 ; Klieosoma Hicks & Schriever, (1904) and later discussed in a very detailed manner 1985 ; Lineosoma Wells, 1965 ; Microsetella Brady & by Olofsson (1917), who also provided a key to the fi­ Robertson, 1873 ; Noodtiella Wells, 1965 ; Pseudecti- ve genera known at that time. The family name was nosoma Kunz, 1935 ; Pseudobradya Sars, 1904 ; Sig- corrected to Ectinosomatidae by Moore (1978), accor­ matidium Giesbrecht, 1881 ; Ectinosomella Sars, 1910 ; ding to the International Code of Zoological Nomen­ Ectinosomoides Nicholls, 1945 ; Oikopus Wells, 1967 ; clature. Further systematic changes at the family level Peltobradya Médioni & Soyer, 1967 ; and Tetanopsis were made by Lang (1944,1948, 1965). He also provi­ Brady, 1910. Last five genera are monospecific, and ded very useful keys to genera, 10 in 1948 and 14 in the genus Bradya is subdivided into two subgenera : 1965. The family Ectinosomatidae presently encom­ Bradya s. sir. and Parabradya Lang, 1944. Only the passes about 232 species and subspecies, classified in­ genus Pseudectinosoma is predominantly freshwater. to 19 valid genera (Bodin 1997) : Arenosetella Wilson, All of the others are marine genera, some of which 1932 ; Bradya Boeck, 1972 ; Bradyellopsis Brian, contain a few freshwater species. Lang (1965) noted two distinct lines of evolution within the farnily Ecti­ nosomatidae : one which comprises genera with a rec­ tangular céphalothorax and linear body shape, and other with a céphalothorax gradually attenuated ante­ 1. Western Australian Museum, Francis Street, Perth, W.A. 6000, riorly and fusiform body shape. Australia. 2. Dipartimento di Scienze Ambientali, Universita di L'Aquila, Via The genus Halectinosoma is the largest in the fami­ Vetoio 14, 67100 L'Aquila, Italy. ly, currently encompassing 57 valid species. Initially it Article available at http://www.limnology-journal.org or http://dx.doi.org/10.1051/limn/2001025 282 T. KARANOVIC, G.L. PESCE (2) was established as a subgenus of the genus Ectinoso­ and new species, Rangabradya indica. At present no ma, with the following short diagnosis (Lang 1944) : other known species of the family Ectinosomatidae "Exp. R5 mit 3 Rand- und 1 Flachenborste, welch letz- can be placed into the new genus with certainty. tere evtl. fehlen kann." Exactly the same was repeated later (Lang 1948), but unfortunately Lang also this ti­ 2. Methods me omitted to designate the type species. This was do­ ne by Vervoort (1962), who designated Ectinosoma The sample was taken with a plankton net (mesh si­ sarsi Boeck, 1872. Lang (1965) elevated Halectinoso­ ze 0.07 mm), by filtering the groundwater for about ma to the generic level, although he did not mention eight hours, and fixed in 5 % formaldehyde. Copepods Vervoort's designation of the type species. Unfortuna­ were separated and transferred to 70 % ethanol. Speci­ tely Halectinosoma sarsi (Boeck 1972) was placed as mens were dissected in Faure's medium, which was incertae sedis by Clément & Moore (1995), so the ge­ prepared following the procedure discussed by Stock nus is now without a recognizable type species. Lang's & Vaupel Klein (1996). Dissected appendages were (1944, 1948) division of Halectinosoma into the "sar­ covered with a coverslip. For the urosome or the who­ si"-group (where the third exopodite segment of the se­ le animal two human hairs were mounted between the cond, third and fourth swimming legs bear 3 outer slide and coverslip, so the parts could not be squashed. spines) and the "ci/riîcorae"-group (where the third By moving the coverslip carefully by hand, the whole exopodite segment of at least the fourth swimming leg animal or a particular appendage could be positioned bears 2 outer spines) was later (Lang 1965) considered in different aspects, making possible the observation unworkable. Although the detailed morphology is qui­ of morphological details. During the examination wa­ te conservative within the genus, some of its species ter slowly evaporated, and appendages or whole ani­ have obviously been misplaced and should be referred mals eventually remained in completely dry Faure's to other genera. One of them, H. porosum Wells, 1967, medium. All drawings were prepared using a drawing was formally transfered to the genus Ectinosoma by attachment (tube) on a Leica-DMLS brightfield com­ Huys & Bodin (1997). Some others probably belong to pound microscope, with C-PLAN achromatic objec­ unde scribed genera, which we will discuss later. Ho­ tives. Specimens which were not drawn were exami­ wever, the systematic of the genus Halectinosoma is ned in a mixture of equal parts of distilled water and problematic and species identification is very difficult glycerol and, after examination, were again preserved due to the inadequacy of most of the descriptions in the in 70 % ethanol. literature (Clément & Moore 1995). This genus is in­ deed much closer to the genus Pseudobradya than to 3. Description Ectinosoma, from which it was segregated. One of the characters that is traditionally used to distinguish Ha­ Order : Harpacticoida Sars, 1903 lectinosoma from Pseudobradya is the condensed Family : Ectinosomatidae Sars, 1904 maxillary endopodite in the former (Huys & Bodin 1997). Also, the position of the inner setae on the Genus : Rangabradya n. gen. maxillary basis can be used as a very good distingui­ Diagnosis shing character between these two genera (they are al­ Small Ectinosomatidae with fusiform habitus. Surfa­ ways situated near the top of the basis in Pseudobra­ ce of body somites with numerous small pores and so­ dya). Probably the subgeneric status of Halectinosoma me sensillae. Rostrum broadly rounded. Female geni­ (of the genus Pseudobradya) would be more appro­ tal double-somite without any trace of subdivision. priate, but the entire generic complex is in need of re­ Posterior edge of furcal rami dorsally and ventrally vision which is beyond the scope of this paper. terminating as acuminate lappets. Female antennula 5- We had an opportunity to examine material collected segmented, short ; third segment longest. Antenna from a freshwater well in India and kindly placed at with 3-segmented exopodite ; first segment smooth, our disposal by Dr Ranga Reddy (Nagarjuna Universi­ second armed with 1 lateral seta, third segment bearing ty). This material is especially similar to some species 1 subapical seta and 1 very strong spine, almost as of Halectinosoma with dubious taxonomic status and broad as segment. Mandíbula with 2 very strong spines displaying some unusual character reductions. Howe­ at ventral base of pars incisiva ; exopodite small, ar­ ver, after detailed examination it was clear that the ma­ med with only 2 setae. Maxillula with highly mobile terial from India cannot be placed within the genus arthrite of precoxa ; coxa, basis and endopodite com­ Halectinosoma and we describe it here as a new genus pletely fused ; endopodite apically bearing 3 setae. (3) A NEW GENUS AND SPECIES OF THE FAMILY ECTINOSOMATIDAE 283 Maxilla with elongate syncoxa ; proximal endite situa­ Etymology ted at first half ; basis as long as syncoxa, armed with The species name is taken from the name of the Re­ 2 setae on about middle of inner edge ; endopodite public of India where the material was collected, i.e. as condensed, bearing 2 stout geniculate setae. Maxilli- an adjective agreeing in gender with the ferninine ge­ ped 3-segmented ; first segment short, armed with neric name. 1 very long seta ; second segment twice as long as wi­ de, unarmed ; third segment as long as first one, armed 3.1. Description of female (holotype) with 3 setae, apicalmost of which shortest. All swim­ Body length, excluding furcal setae, 0.374 mm. Ha­ ming legs with 3-segmented exopodites and endopo- bitus fusiform and robust, greatest width at hind