Pseudechinopsyllus George, 2006

George, Kai Horst, Wandeness, Adriane P. & Santos, Paulo J. P., 2025, A new species of Pseudechinopsyllus George, 2006 (Copepoda, Harpacticoida, Cletodidae) from Campos Basin, Brazil (southwest Atlantic Ocean), with remarks on the phylogeny of the genus, ZooKeys 1241, pp. 325-357 : 325-357

Genus Pseudechinopsyllus George, 2006

Generic diagnosis.

Cletodidae T. Scott, 1905 , Cletodinae T. Scott, 1905 , Ceratonotus group sensu Conroy-Dalton (2001). Body remarkably long and slender, female length from rostrum to end of FR between 1,100 and 1,400 µm, males somewhat smaller. Cphth frontally with strongly developed “ peak ”, with or without FLH, ACST present, and with four pairs of long tube pores. CLVPa and CLVPp well developed. Rostrum small, constricted and almost squarish or strongly elongated, apically with pair of sensilla, long tube pore, and RST. CLDP well developed or absent. Free thoracic somites bearing P 2 – P 5 laterally with TST 1 – TST 4, DP 1 – DP 4 long, unarmed, with sensilla at their tips; dorsally and dorsoventrally bearing long tube pores. Females with last thoracic and first abdominal somite fused to GDS; former separation still indicated by dorsal suture; GST developed. GDS and remaining abdominal somites except telson also carrying dorsal and dorsoventral tube pores. Abdominal somites with or without AST 1 – AST 3, whilst AST 4 are missing in both known species. Telson at the most as large as the previous somite, laterally with two pairs of tube pores; anal operculum with dense row of fine long spinules at apical margin. FR very long and slender, reaching a length-width ratio between 10 / 1 and 14.8 / 1. All seven furcal setae present. Female A 1 four-segmented, aes on third and fourth segment. Male A 1 eight-segmented, haplocer. A 2 lacking exopod, with allobasis bearing two abexopodal setae; endopod with two bipinnate spines and one small bare seta at anterior margin; apically with six elements, three (or 4) of which long and geniculate. Mouthparts overlapped by big labrum. Md with one-segmented palp, carrying basal seta no. 2 and endopodal setae nos. 3–5; setae no. 1 and no. 6 completely reduced. Mxl with distinct coxa that bears one apical seta; basis also separated, with two lateral and two or three apical setae. Mx with two endites and distinct allobasis; endopod distinct, small and knob-like, carrying two setae. Mxp with syncoxa and basis; both segments equipped with small and / or long spinules; syncoxa without seta; basis longer than syncoxa, outer margin convex; endopod produced into long, curved, and bare claw that is longer than the endopod and accompanied by a smaller bare seta. P 1 – P 4 with transversely elongated bases that are covered by long spinules and carry a long tube pore at the anterior margin. Intercoxal sclerites transversely long, bow-like. Coxae small, trapezoid or rectangular in shape. P 1 lacking endopod; basis with one outer bare or bipinnate and one inner bare seta that is located close to the coxa and arises from a protruded pedestal; exopod 2 - segmented, exp 1 with bipinnate outer spine, exp 2 much longer than exp 1, with one bipinnate outer spine and four geniculate apical setae; subapically with one tube pore. P 2 – P 4 with three-segmented exopods; exp 3 with 1: 2: 1 inner setae, respectively. P 2 lacking endopod, female P 3 and P 4 each with one-segmented tiny endopod that bears one bare seta; male P 3 and P 4 endopods two-segmented, P 3 enp 2 additionally with long curved apophysis. Female P 5 with basoendopod and fused or distinct exopod. Outer basoendopodal seta located on an extremely elongated and slender setophore, which is basally accompanied by one long tube pore. Endopodal lobe narrow but elongated, (sub) apically with two or three tube pores and two setae, one of which long and bipinnate, the other one small and bare. Exopod (al lobe) elongate, carrying two outer, two apical, and one subapical inner seta; additionally subapically with long tube pore. Male P 5 with distinct endo- and exopod. Type species: Pseudechinopsyllus sindemarkae George, 2006 ; additional species: P. andrei sp. nov. (present contribution).