Odaginiceps korykosensis, Karaytug, Suphan, Sak, Serdar & Alper, Alp, 2010

Karaytug, Suphan, Sak, Serdar & Alper, Alp, 2010, A new species of Odaginiceps Fiers, 1995 (Copepoda, Harpacticoida, Tetragonicipitidae) from the Mediterranean coast of Turkey, ZooKeys 53, pp. 1-12 : 3-10

Odaginiceps korykosensis sp. n. Figs 16

Type locality.

Turkey, Mediterranean coast, Mersin Province; intertidal zone of Kızkalesi beach (36°27.473'N; 34°08.647'E). The type locality is fine sand beach.

Material examined:

Holotype ♀ dissected on seven slides. Allotype ♂ dissected on six slides. Legs. S. Karaytuğ, S. Sak, A. Alper and S. Sönmez.

Description.

Female (Fig. 1A, B).Total body length 770 µm, with largest width measured at cephalothorax. Integument of cephalic shield smooth, of all other somites ornamented with irregular pattern of hardly visible spinules. Body surface with sensilla pattern as figured. Posterior margin of the body somites with serrate hyaline frills.

Rostrum (Fig. 1A) large, widest at base, extending halfway along second antennular segment; with two delicate sensillae and a mid-dorsal pore.

Urosome (Figs 1A, B) 5-segmented, comprising P5-bearing somite, genital double somite and three free abdominal somites. Genital double-somite longer than wide; with transverse surface ridge dorsally and laterally (Fig. 1B) extending ventrally (Figs 1A; 2A), indicating original segmentation. Genital field (Fig. 2A) with small copulatory pore located in median triangular depression. A spermatophore attached to the copulatory pore. First and second somite of genital double-somite and second and third abdominal somites with continuous spinules near distal margin dorsally (spinules of first somite of genital double-somite interrupted midway) (Fig. 1A); genital double somite and second abdominal somite with spinular row near distal margin ventrally, interrupted midway; third abdominal somite with continuous spinular row near distal margin ventrally (Fig. 2A). Anal somite (Fig. 1A) with distal spinular row extending dorsally to the either side of anal operculum; operculum smooth, slightly convex.

Caudal rami (Figs 1C; 3D, E) tapering posteriorly with 4-5 dorsal spinules distally near the base of seta V; 1.7 times longer than wide; inner margin ornamented with spinules (Fig. 3D); with a pore on proximal third of dorsal surface (Fig. 3D), another pore present on ventral surface near the base of seta III (Fig. 2A); with seven setae (Fig. 3D, E), seta I minute located near the base of seta II; setae II–III bare; setae IV–V strongly developed and bipinnate; seta V with swollen sinuate base; seta VI short and as long as seta III; seta VII tri-articulated.

Antennule (Fig. 3A) 9-segmented; segment 1 with a long plumose seta at anterodistal margin, a spinular row on anterior surface, long spinules along inner margin, small tube-pore on dorsal surface near inner margin. Segment 2 with long spinules on caudal margin. Segment 4 with long aesthetasc fused basally to seta. Segment 9 longest, bears an apical acrothek consisting of a short aesthetasc and two setae. Armature formula 1-[1 plumose], 2-[6+3 plumose], 3-[6+1 plumose], 4-[3+(1+ae)], 5-[2], 6-[2+2 plumose], 7-[2], 8-[1+1 plumose], 9-[5+acrothek].

Antenna (Fig. 3B). Coxa small and smooth. Basis with 2 long spinules at outer margin. Exopod 1-segmented with one lateral pinnate seta, apical armature consists of one pinnate seta and one pinnate spine; a few spinules present around outer distal corner and midway along outer margin. Endopod 2-segmented; first endopod segment with one plumose seta at proximal third of outer margin. Distal endopod segment with various spinular rows as figured and with two abexopodal unipinnate spines laterally (both spines with subapical tubular extension). Apical armature of enp-2 consisting of two pinnate setae, and five geniculate setae; longest geniculate seta with large spinules and fused at base to long pinnate seta.

Labrum (Fig. 4D). Free margin straight, with spinular row at distal corners and fine spinular row subdistally on ventral surface.

Mandible (Fig. 4A, B). Coxa robust, gnathobase with one pinnate seta at dorsal corner and several blunt multicuspidate teeth along distal margin. Palp biramous; basis strong, with three plumose setae along inner margin, ornamented with a group of long spinules proximally. Exopod 3-segmented, first segment with two plumose setae, second segment with two bare setae and third segment with two bare setae fused at base. Endopod 1-segmented with two lateral and six distal bare setae (two inner distal setae and two outer distal setae fused at base).

Maxillule (Fig. 4E). Praecoxal arthrite with seven spines around distal margin, with spinules as figured; anterior surface with two bare setae; posterior surface with three plumose and one pinnate setae. Coxal endite with two smooth and four plumose setae. Basis with seven bare and one unipinnate setae. Long endopod segment and square exopod segment each with three plumose setae. Endopod and exopod with a row of fine marginal setules.

Maxilla (Fig. 4C). Syncoxa ornamented with spinules as figured; with three endites. Proximal endite with one plumose and three unipinnate setae; middle endite with three unipinnate setae; distal endite with two unipinnate and one plumose setae. Allobasis drawn out into pinnate claw; accessory armature consisting of two bare setae and one curved spine. Endopod 2-segmented; proximal segment with one bare seta, distal segment with one geniculate and two bare setae.

Maxilliped (Fig. 4F). Subchelate and ornamented with spinular rows as figured. Syncoxa with three inner bare setae subdistally. Basis with two bare setae along inner margin. Endopod with one small accessory seta, one bare and two plumose setae.

P 1 (Fig. 5A). Intercoxal sclerite rectangular and smooth. Small praecoxa triangular and bare. Coxa with complex spinular ornamentation anteriorly as figured. Basis narrower than coxa; anterior surface with pore near the base of outer bipinnate spine; inner side with long slender spinules. Exopod 3-segmented, segments with spinular rows along inner and outer margins. Endopod 2-segmented; enp-1 reaching almost middle of exp-3, with spinular row along inner and outer margins; long inner seta plumose and located subdistally; enp-2 slightly shorter than enp-1, with spinules along inner and outer margins and with two long articulated setae and one small inner apical seta.

P2-P4 (Fig. 5 B–D). Intercoxal sclerite unornamented. Coxa and basis with complex spinular ornamentation as figured. Exopod 3-segmented. Endopod 2-segmented. Endopodal and exopodal segments with spinular rows along inner and outer margins. Exp-1 of P2-P3 without spinules along inner margin. Enp-1 of P2 without inner seta. Terminal outer seta of P2 enp-2 bare. P4 exp-2 with one plumose inner seta. With a pore on anterior surface of enp-2 and anterior surface of exp-2 and -3. Exp-1 and -2 (and -3 in P4) with a posterior spinule patches. Enp-2 with a posterior spinular row subdistally.

Armature formula of swimming legs:

P5 (Fig. 3C). Baseoendopod and exopod covered with fine spinules on anterior surface, with long slender spinules along inner and outer margins. Exopod 3.6 times longer than wide, with 6 setae; seta 1 longest and plumose; seta 3 smallest and bare. Baseoendopod longer than wide; with 2 unipinnate and 3 plumose setae.

P6 (Fig. 2A) represented by a small segment with one outer plumose seta and two slender bare setae.

Description.

Male (Fig. 6A). Total body length 510 µm. Body smaller and more slender than female, largest width measured at midway of cephalothorax. Body ornamentation generally as in female. Sexual dimorphism observed in antennule, P2-P6 and genital segmentation.

Antennule (Fig. 6C, D) indistinctly 10-segmented, sub-chirocer. Segment 1 short, with small tube-pore on dorsal surface and with long spinules along caudal margin. Segment 2 longest. Segment 4 with partial suture line dorsally. Segment 5 with long aesthetasc fused basally to seta. Segment 10 bears an apical acrothek consisting of a short aesthetasc and two slender setae. Armature formula 1-[1 plumose], 2-[7+3 plumose], 3-[4], 4-[4+1 plumose], 5-[4+1 spine+(1+ae)], 6-[1+2 spines], 7-[2], 8-[1], 9-[2], 10-[5+acrothek].

P2 enp-2 (Fig. 1D); outer terminal spine more robust than female; middle terminal seta bare, shorter than female and as long as outer spine; inner terminal seta minute. P3 enp-2 (Fig. 1E); inner terminal seta modified to a short spine (arrowed in fig. 1E). P4 exp-3 (Fig. 1F) with 6 setae, inner terminal seta of female (arrowed in fig. 5D) absent in the male.

P5 biramous (Fig. 6B), fused medially. Baseoendopod ornamented with patch of spinules as figured; with two pores (one near the base of outer basal seta and the other near the base of inner terminal spine of endopodal lobe); endopodal lobe with one lateral and two distal spines. Exopod with three outer bare setae, 1 terminal bare seta and two inner unipinnate setae; with two pores (one tube pore near the base of outer proximal bare seta and the other near the base of outer median bare seta). P6 vestiges asymmetrical (Fig. 2B); each P6 with one plumose inner seta and two long bare setae.

Etymology.

The specific name refers to “korykos” which is the historical name of Kızkalesi province (Mersin, TURKEY).