Spinopedia, Gómez & Corgosinho & Rivera-Sánchez, 2021

Gómez, Samuel, Corgosinho, Paulo Henrique Costa & Rivera-Sánchez, Karen I., 2021, Proposal of new genera and species of the subfamily Diosaccinae (Copepoda: Harpacticoida: Miraciidae), European Journal of Taxonomy 759 (1), pp. 1-62 : 41-42

Spinopedia gen. nov.

urn:lsid:zoobank.org:act:F6DD1CA7-26EE-476D-AC00-2C4401B63014

Bulbamphiascus Lang, 1944: 19 , pro parte.

Type and only species

Bulbamphiascus spinulosus Mu & Gee, 2000 (= Spinopedia spinulosa ( Mu & Gee, 2000) comb. nov.), by monotypy.

Diagnosis

Miraciidae : Diosaccinae . Body fusiform; body surface seemingly covered with minute denticles. Rostrum not fused to cephalothorax, triangular, elongate, with round apical margin, almost as long as first and second antennulary segments combined, with one subdistal sensilla on each side at third quarter of its length. Pro- and urosomites without extensions; with a flexible unsclerotized cuticle between prosome and urosome. First urosomite (P5-bearing somite) narrower than preceding somites in dorsal view. Genital double-somite (genital – second urosomite – and third urosomites fused) completely fused ventrally, with a dorsolateral cuticular rib marking original division between genital and third urosomites. Telson trapezoidal, without anal operculum. Caudal rami short, about 1.5 times as wide as long in dorsal view, with seven setae. Female antennule eight-segmented, with aesthetasc and seta fused basally on fourth segment and with apical acrothek on last segment. Male antennule haplocer, 10-segmented, with aesthetasc and seta fused basally on fifth segment and with apical acrothek on last segment. Setae of first and second antennulary segments typically bipinnate, smooth in remaining segments. Antenna with allobasis and abexopodal seta; exopod three-segmented, armature formula 1-1-1,3,0. Mandibular palp biramous; endopod one-segmented, larger than exopod, the latter two-segmented. Maxillule biramous; rami one-segmented. Maxilla with three endites, proximal and middle endites with two, distal endite with three elements; ENP one-segmented. Maxilliped subchelate; (syn)coxa with four, basis with two setae; ENP one-segmented, with claw and three accompanying setae. P1–P4 with three-segmented rami. Male P1 basis sexually dimorphic, with inner unipinnate spine and inner modified accessory spine. P1 EXP shorter than ENP, reaching tip of ENP2; P1 ENP1 with strong bipinnate inner seta; P1 ENP3 2.5 times as long as ENP2, with one small inner seta, a distal long geniculate seta and one outer spine; P1 EXP2 with inner seta; P2–P4 EXP and ENP of approximately the same length. P2–P4 EXP1 with inner seta; inner distal seta of P2–P4 EXP3 visibly smaller than other inner setae on same segment. P2 ENP2 with two setae, proximalmost shorter. P2–P4 basis with inner chitinous projection. Male P2 ENP sexually dimorphic, two-segmented; first segment with one inner seta; second segment completely covered by spinules and setules of different lengths, with two inner setae subequal in length, two elements (one medial, one apical) issuing from elongate cylindrical extension fused to segment basally, and with one inner subdistal sigmoid blunt element and one outer subdistal blunt spine with almost parallel margins, viz slightly tapering distally, of which the former is shorter. P5 EXP longer than wide, comparatively shorter in male, with six setae in both sexes; two medial outer elements modified into stiff short spines in male; distal outer spine foliaceous in female. P5 endopodal lobe with five setae in female, with two setae in male; armature of male P5 endopodal lobe strongly bipinnate.

Armature formula of P1–P5 as follows:

Sexual dimorphism expressed in male antennule, P2 ENP, P5, P6, and in separated genital and third urosomites.

Etymology

The prefix ‘spino’ from the Latin ‘spīna’, ‘spine’, and the sufix ‘pedia’ from the Latin ‘pēs’, ‘pedis’, ‘foot’, refers to the presence of a spinular patch on the male P2 ENP1, and to the presence of several spinules and setules covering the male P2 ENP2. Gender feminine.

Apomorphies for Spinopedia gen. nov.

Two apomorphies for Spinopedia have been detected: i) presence of an inner subdistal spinular patch on the male P2 ENP1 and ii) male P2 ENP2 completely covered with spinules and setules of different lengths. In addition, the subdistal inner seta of the female P5 EXP arises directly from the ramus (i.e., the seta does not arise from a setophore) (character 42 in Table 3 ; see also Fig. 19 ). The lack of a setophore for the subdistal inner seta of the female P5 EXP is regarded here as autapomorphic for the genus and is a result of reversal. The presence of a setophore for the inner subdistal seta of the female P5 EXP is autapomorphic for a larger group of genera to which Spinopedia gen. nov. belongs ( Fig. 19 ) and seems to have evolved convergently in more than one evolutionary lineage within the Diosaccinae ( Fig. 19 ).

Figures

Fig. 19. Strict consensus cladogram of the generic relationships within the Diosaccinae.

Armature formula of P1–P5 as follows: