Thalestrella psammophila ( Wells, 1967 ) 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 : 285-286

Thalestrella psammophila ( Wells, 1967) comb. nov.

Karllangia psammophila Wells, 1967

Original description. Wells (1967): 292–294; Text-fig. 52.

Type locality. Mozambique, Inhaca Island ; Ilha dos Portuguesos (Elephant Isle); intertidal zone, clean sand .

Notes. Karllangia psammophila was originally described as a distinct species ( Wells 1967: 292) but subsequently relegated by Wells & Rao (1987: 132) to a subspecies of K. arenicola along with another form ( K. arenicola bengalensis ) they described from material collected in the Andaman and Nicobar Islands. Wells & Rao claimed that K. arenicola was identical to K. psammophila in every single aspect except for the lack in both sexes of an attenuated outer distal corner on the posterior margin of the first antennulary segment. However, Gee (2006) reinstated the latter and K. arenicola bengalensis to full species status based on significant differences in the armature of the swimming legs and the ornamentation of the anal operculum. The author also examined paratype specimens of K. psammophila , revealing oversights in Wells’s (1967) description of the antenna (abexopodal margin of allobasis with seta; ♀ exopod with two setae on exp-1 and one lateral and two distal setae on exp-2), mandible (basis with three setae; exopod small, with two setae) and maxilliped (syncoxa with one seta; basis with two setae on palmar margin), and suspected that similar corrections apply to K. bengalensis .

Thalestrella psammophila shares the presence of only five elements on the female P5 exopod with T. obscura comb. nov. and T. bengalensis comb. nov., however, it differs from the former in the presence of well developed, denticulodigitate hyaline frills on the body somites and the presence of an inner seta on P1 exp-2, and from the latter by the attenuated outer corner of the proximal antennulary segment in both sexes, the second outer seta of the female P5 exopod being distinctly longer (vs shorter) than the proximalmost seta, and the proximal outer seta of the male P5 exopod distinctly shorter (vs longer) than the segment.