Acanthochondria zebriae, Ho, Kim I.H. & Kumar, 2000

Ju-Shey, 2000, Chondracanthid copepods parasitic on flatfishes of Kerala, India, Journal of Natural History 34 (5), pp. 709-735 : 711

Acanthochondria zebriae sp. nov.

(®gures 1±2)

Material examined. Twenty-four adult and three juvenile mm (19 with attached l) on gill ®laments of Zebrias synaturoide s (Gilchrist): four adults and three juveniles collected on 11 March 1994 and 20 adults collected on 26 December 1994. Holotype ( USNM 285490 ) and eight paratypes ( USNM 285491 ) have been deposited in the US National Museum of Natural History, Smithsonian Institution , Washington, DC and the remaining paratypes and other specimens kept in the junior authors’ (IHK) collection.

Female. Body (®gure 1A) elongated and cylindrical, measuring 1.69±1.94 mm long. Head (®gure 1B) longer than wide, 403Ö 273 m m (not including ināted antennule), with small rounded knob at each anterolateral corner and ventrally protruded oral region (®gure 1C). First pediger narrower than head. Second pediger with remaining prosomal somites fused into a long, cylindrical trunk bearing a pair of posterolateral processes (®gures 1D, E). Genital double somite slightly longer than wide, 135Ö 123 m m, and abdomen distinctly wider than long, 37Ö 65 m m. Caudal ramus (®gure 1D) a spiniform, pointed process bearing four setae. Egg sac about as long as trunk.

Antennule (®gure 1F) ¯eshy and ināted; armature being (from proximal to distal) 1-1-2-2-2-7. Antenna (®gure 1G) two-segmented; terminal segment sharply curved and covered with minute tubercles on terminal area of basal half before bend. Labrum with smooth, straight posterior margin. Mandible (®gure 1H) twosegmented; terminal blade with 31 to 33 teeth on convex (inner) side and 28 to 32 teeth on concave (outer) side. Paragnath (®gure 1I) a small spinulose lobe. Maxillule (®gure 1J) with two terminal elements. Maxilla (®gure 1K) two-segmented; ®rst segment robust and unarmed; second segment bearing one small, simple, basal seta, one large seta with hyaline tip and a row of 22 to 29 teeth on terminal process. Maxilliped (®gure 2A) three-segmented; ®rst segment largest but unarmed, second segment with long spines on greatly protruded inner distal corner, and terminal segment reduced to a small hook situated opposite to tuft of spinules on inner-distal corner of second segment. Both leg 1 (®gure 2B) and leg 2 (®gure C) nearly unilobate, with ināted, bluntly pointed exopod continuous with protopod and carrying a much reduced endopod tipped with a seta. Terminal region of exopod with six setae on leg 1 and four setae on leg 2.

Male. Body (®gure 2D) 217 m m long, with swollen cephalosome and cylindrical metasome and urosome. Genital somite (®gure 2E) with usual ventrolateral ridges. Abdomen (®gure 2E) indistinguishably fused with genital segment. Caudal ramus as in female but naked. Antennule reduced to a simple seta (see ®gure 2D). Antenna (®gure 2F) with small seta on basal segment and a conical process on basal part of terminal hook. Mandible (®gure 2G) with fewer teeth on terminal blade, 17 on convex side and ten on concave side. Maxilla (®gure 2H) with eight or nine teeth on inner side and single one on outside of terminal process. Maxilliped (®gure 2I) essentially as in female, but terminal claw relatively larger. Leg 1 (®gures 2D, J) reduced to a simple spiniform seta. Leg 2 absent.

Etymology. The speci®c name zebriae refers to the host of the present species.

Remarks. According to Ho and Kim’s (1995) designation of the variable appendages useful in species identi®cation in the genus Acanthochondria , the antennule of the new species belongs, undoubtedly, to Type G±I, but its legs do not ®t well to any of the ®ve types. Basically, the legs of A. zebriae are attributable to Type A, but no species of Acanthochondria with Type A leg has its endopods on both legs 1 and 2 reduced to a small knob as in the present species. Furthermore, no species of Acanthochondria has the male with leg 2 missing and leg 1 reduced to a spiniform seta. The subchelate female maxilliped is another unusual feature of the present species.