Nitokra affinis colombiensis, Fuentes-Reines, Juan M. & Suarez-Morales, Eduardo, 2014

Fuentes-Reines, Juan M. & Suarez-Morales, Eduardo, 2014, A new subspecies of Nitokra affinis Gurney, 1927 (Copepoda, Harpacticoida) from the Caribbean coast of Colombia, ZooKeys 378, pp. 1-15 : 2-8

Nitokra affinis colombiensis ssp. n.

Material examined.

One female holotype (UARC133M) and one male allotype (UARC134M), ethanol-preserved. Paratypes: one female (UARC142M-147M) and one male (UARC136M-141M), plus two females and two males (UARC135M). Additional material: Six adult females, four adult males in authors’ (JF-R) personal collection. Two adult females, two adult males from same locality and date (ECO-CHZ-09088).

Type locality.

Laguna Navío Quebrado, La Guajira, Colombia (11°25'N, 73°5'W).

Female.

Habitus in lateral view as in Figure 1A. Body subcylindrical, tapering posteriorly, total body length measured from tip of rostrum to posterior margin of caudal rami ranging from 588 to 714 μm (average 660 μm, n = 6; holotype: 700 μm). Rostrum subtriangular with 2 sensilla and apical rostral projection which is about half the length of rostrum (Fig. 3H). Genital double-somite distinct dorsally and laterally, with partial ventral suture (Fig. 2A, B). Anterior ventral surface of genital somite with incomplete rows of spinules on medial outer surface, distal row of spinules and pair of sensilla. Succeeding urosomite with dorsal incomplete row of spinules on medial surface and distal row of spinules covering lateral margin and only part of ventral margin (Fig. 2A, B); same somite with ventral curved row of minute spinules on central surface, incomplete row on medial outer margin and 2 sensilla on posterior margin. Preanal somite with similar ornamentation pattern except for spinules encircling posterior margin of somite, absence of curved row on ventral surface and additional row of minute spinules. Anal somite with ventral and dorsal rows of spinules along posterior margin bordering insertion of caudal rami; anal operculum semicircular, ornamented with 14-20 large spinules, flanked by 2 sensilla and rows of minute spinules (Figs 1C, 2B). Caudal ramus short, subquadrate, with rounded margins, armed with 6 setae, seta I small, seta II as long as seta I, seta III on distal outer position, about 1.5 times as long as setae I and II. Setae IV and V thick, long, the former being longest; seta VI slightly longer than seta III. Dorsal seta VII uniarticulate at base. Ramus ornamented with spinules at insertion of setae (Figs 1F, 2A, B).

Antennule. 8-segmented, second segment about 1.5 longer than first and third segments, aesthetasc on fourth segment reaching well beyond distal end of terminal segment (Fig. 3A). Second segment longest, about 1.5 times as long as third segment and 2.1 times longer than preceding first segment. Fourth segment about as long as third segment. Armature as follows: 1(1), 2(7), 3(7), 4(3+aes), 5(2), 6(3), 7(3), 8(7).

Antenna. Basis with group of 5 unequal spiniform setae, first endopodal segment subrectangular, smooth, second endopodal segment with subdistal row of spinules on inner margin, with 2 lateral inner spines and 6 distal elements, outermost two of them basally fused at insertion. Exopod one-segmented with 3 setae, 2 pinnate and 1 smooth seta (Fig. 3B).

Mandible. Gnathobase with 5 large teeth, and long dorsal seta ornamented with short spinules (Fig. 3C). Mandibular palp 2-segmented, first segment (basis) with 2 setae. Endopodal segment with 1 short lateral and 4 long apical setae (Fig. 3D).

Maxillule. Arthrite of praecoxa ornamented with group of subequal spinules, arthrite armed with 2 subdistal setae and 4 distal elements. Coxal endite with 2 setae. Basis with 4 setae; exopod 1-segmented, with 2 setae, one slender, the other thicker, distally serrate (Fig. 3E).

Maxilla. Syncoxa naked, with 2 endites, proximalmost with single, slender modified element with distal tuft of setules and with short proximal seta; second endite with 2 unequal setae. Allobasis forming strong serrate claw with 2 accessory setae on proximal position (Fig. 3F).

Maxilliped. Subchelate. Syncoxa with single seta on inner distal corner, basis unarmed, with longitudinal patch of spinules. Endopod drawn into long and slender lightly serrate claw with 2 short accessory setae (Fig. 3G).

P1. Coxa with outer row of slender spinules. Basis with spinules bordering insertion of exopodal and endopodal rami, inner basipodal spine short, stout, reaching 1/3 of length of first endopodal segment. Outer basipodal spine short, stout, spinulated. EXP and ENP 3-segmented. Exopodal ramus shorter than first endopodal segment. Third exopodal segment with 2 apical geniculate setae. First endopodal segment about 2.9 longer than its width; third endopodal segment with terminal claw, the latter about 1.5 times as long as segment (Fig. 4A).

P 2. Coxa with outer row of slender spinules. Basipod with 2 groups of spinules, as figured. Exopod and endopod 3-segmented. Exopod endopod equally long. First exopodal segment without inner seta, second and third exopodal segments with inner seta. Exopod without modified setae, outer margin of exopodal segments spinulated. Endopod 3-segmented, outer margin of segments ornamented with spinules (Fig. 4B).

P3. Coxa with outer row of slender spinules. Basipod with spinules only at insertion of outer basipodal seta. Exopodal and endopodal rami as in P2 except for shorter apical spiniform element (arrowed in Fig. 4C) and endopod slightly shorter than exopod (Fig. 4C).

P4. Coxa with outer row of slender spinules. Basipod as in P3. EXP longer than ENP (Fig. 4D). Middle inner seta of EXP3 thicker and longer than adjacent setae (arrowed in Fig. 4D).

P5. EXP subrectangular, about 1.66 longer than it is width, with 6 setae. Relative length of exopodal setae from inner to outer element as follows: 0.81, 1.00, 0.18, 0.38, 0.18, 0.56. Endopodal lobe quadrate, reaching almost halflength of EXP, with 5 spinulose setae, outermost being longest; relative length of setae from inner to outer elements as follows: 0.32, 0.37; 0.43, 1, 0.46 (Fig. 6A).

Armature formula of female P1-P5 as follows:

P 6. Represented by narrow plate with subdistal lobe-like process marked by a notch (arrowed in Fig. 2A); plate bearing 3 elements, 2 equal slender setae and outer small spinulated seta (Fig. 6B).

Male.

Smaller than female, habitus in lateral view as in figure 1B. Total body length ranging from 518 to 574 μm (mean, 546 μm; n = 4; allotype: 518 μm). Ornamentation of urosomites resembling that of female except for position of rows of minute spinules on ventral surface of genital and preanal somites (Fig. 2C, D). Anal somite with row of small spinules on posterior margin at insertion of caudal rami. (Figs 1D, E, 2C, D). Rostrum, antennae and mouthparts as in female.

P1. As in female except for an additional row of spinules on the coxa, presence of small slender seta and 1 geniculate apical seta (arrowed in Fig. 5A), instead of 2 on ENP3, slenderer ENP1, and dimorphic modified inner basipodal spine (Fig. 5A, B).

P2-P4. As in female (Fig. 5C-E), including thickened middle inner seta of EXP3 (arrowed in Fig. 5E) which is relatively shorter than in female.

P5. EXP subquadrate, armed with 6 setae, distal innermost being longest, reaching midlength of fourth urosomite (Fig. 2C, D). Baseoendopod with 3 unequally long setae, middle one longest, about twice as long as the other two (Fig. 6C).

P6. With 2 unequal seta, inner one three times longer than outer seta (Figure 6D). Caudal rami as in female (Fig. 2C, D).

Variability. One male with 2 elements (instead of3) on ENP3 of P1.

Etymology.

The new subspecies is named after Colombia, the country from which it was first discovered.

Habitat.

The estuary Laguna Navío Quebrado has a surface area of 10.7 km2; it is characterized by the presence of an oyster bank in the limnetic area and vegetation (mangrove and beds of macrophytes) in the littoral zone. Water temperature ranged between 28 and 31 °C, salinity between 0-28 psu, and pH values were 7.8-8.3.