Karaytugia, Huys, Rony & Mu, Fanghong, 2021

Huys, Rony & Mu, Fanghong, 2021, Johnwellsia, a new intertidal genus of Parastenheliidae (Copepoda, Harpacticoida) from the Taiwan Strait, China, including a review of the family and key to genera, Zootaxa 5051 (1), pp. 236-318 : 295-296

Karaytugia gen. nov.

urn:lsid:zoobank.org:act:3541F2B6-4847-4ECE-B77A-C4D55732718F

Kuru & Karaytuğ (2015) described a new species, Parastenhelia aydini , from a Turkish beach in the Eastern Mediterranean and considered it morphologically most similar to Pa. spinosa . The authors refer to their unpublished observations but it is not clear which “population” they identified as Pa. spinosa . They differentiated Pa. aydini from the latter by the combination of the following characters: (a) ♀ antennule 9-segmented; (b) spinular rows near outer margin of P1–P4 bases significantly reduced; (c) P4 enp-3 with four setae in both sexes; (d) ornamentation of endopodal and exopodal setae of ♀ P5 different; (e) caudal ramus seta V of ♀ not swollen near the base; (f) modified element on the seventh segment of ♂ antennule not present; (g) apophysis on ♂ P3 enp-3 notched; and (h) ♂ P5 exopod 2-segmented, five setae in total .

Unique characters displayed by Pa. aydini include (a) the modification of the endopodal claw on the maxilliped; the distal half does not taper to a sharp tip as in other members of the family, forming instead a spatulate structure fringed with a series of densely arranged serrations around the inner margin and rounded apex; (b) P1 exp-3 with one very long naked seta and three claws of different lengths, the longest one being 0.8 times the length of exp-2; (c) P1 enp-2 claws radically divergent in size, with large one nearly three times longer than short one; (d) inner seta of P2–P3 enp-1 reduced; (e) spinous apophysis on ♂ P3 endopod with foot-shaped tip; and (f) ♂ P5 exopod 2-segmented, with one very long outer seta on exp-1 and four elements on exp-2; the only other species in the Parastenheliidae that display a 2-segmented exopod are Parastenhelia willemvervoorti sp. nov. and Johnwellsia bipartita gen. et sp. nov. which have six short elements, and one spine and two setae, respectively, on exp-2. Based on this combination of apomorphic character states, Pa. aydini is her fixed as the type species of a new genus, Karaytugia gen. nov.

Diagnosis. Parastenheliidae . Sexual dimorphism in antennule, P2–P3 endopods, P5–P6 and urosomal segmentation. Body subcylindrical, short; posterior margin of cephalothorax and somites bearing P2–P5 with plain hyaline frills; remaining urosomites (except anal somite) with serrate hyaline frills. Rostrum defined at base, of moderate size, reaching to about halfway second segment of antennule; elongate triangular. Anal operculum semicircular, bordered with fine spinules. Caudal ramus wider than long, with conspicuous spinular ornamentation; with seven setae, setae IV– V not basally inflated in ♀ .

Antennule elongate and 9-segmented in ♀, segment 1 not elongate, segments 7–8 shortest, with aesthetascs on segments 4 and 9; haplocer and 11-segmented in ♂, with geniculation between segments 7 and 8, segment 5 swollen and with aesthetasc; segmental homologies in ♂: I, II– VIII, IX – XII, XIII, XIV – XVII, XVIII, XIX – XX, XXI – XXII, XXIII, XXIV – XXV, XXVI – XXVIII. Antenna not sexually dimorphic; proximal endopodal segment largely separated from basis, with pinnate seta on abexopodal margin; exopod 2-segmented, proximal segment with two setae, distal segment with two lateral and three apical elements; distal endopodal segment without penicillate elements. Mandible with three elements on basis; endopod with eight setae; exopod 1-segmented, with two setae. Maxillulary coxal epipodite represented by one seta. Maxilla with three endites on syncoxa; endopod discrete, with three setae. Maxilliped with two setae on syncoxa; basis with two setae and longitudinal spinular row on palmar margin; endopod represented by conspicuously serrated claw, accompanied by three accessory setae .

P1 inner basal spine not sexually dimorphic. P1 exopod 3-segmented; exp-2 much longer than others, nearly three times as long as exp-1 and about half as long as enp-1, with short inner seta; exp-3 small, with two pinnate spines, one geniculate seta and one naked seta. P1 endopod 2-segmented; enp-1 elongate, about 1.5 times length of exopod, with short, proximally inserted, pinnate inner seta, segment margins without area of reduced chitinization; enp-2 very small, with one naked minute seta and two dentate claws. P2–P4 rami 3-segmented; inner seta of P2–P3 exp-1 reduced in size, absent in P4. P2–P3 endopods ♂ 3-segmented. P2 slightly more robust in ♂. P3 endopod ♂ without inner setae (vs two in ♀) on enp-3 and outer spine modified into apically truncated spinous apophysis. Armature formula of P2–P4 as follows:

P 5 ♀ endopodal lobe with five setae, outermost well developed, innermost shortest; inner margin without transverse striae. P 5 ♀ exopod elongate, with six elements. P 5 ♂ endopodal lobe with two elements, outer one shortest; exopod 2-segmented, with one long outer seta on exp-1 and four elements on exp-2. Vestigial P 6 ♀ represented by three minute setae. P 6 ♂ with three setae.

Etymology. The genus name is dedicated to Prof. Süphan Karaytuğ (Mersin University, Turkey), in recognition of his contributions to the harpacticoid fauna of Turkey, and under whose mentorship the next generation of harpacticoid experts in his home country emerged. Gender: feminine.

Type and only species. Parastenhelia aydini Kuru & Karaytuğ, 2015 = Karaytugia aydini ( Kuru & Karaytuğ, 2015) comb. nov. (by original designation herein).