Latinopsis patagonica Karanovic & Datry, 2009, gen. nov.

Latinopsis patagonica gen. nov. sp. nov.

(Figures 1–3)

Etymology. The species is named after “Patagonia” from where it was collected.

Material examined: Holotype male (dissected on one slide, TMAG G5897); allotype female (dissected on one slide, TMAG G5898), paratype female (in alcohol, TMAG G5899).

Type locality: PAC BEN2 (locality code); Chile, Region XII: Magallanes and Antártica Chilena Region, Madre de Dios Archipelago, Pacific cave area, 25/01/2006, T.Datry, 50° 22' 35” S / 75° 27' 24”W.

Diagnosis: Postero-dorsal keel on the left valve prominent. Lobe “b” of the hemipenis pointed (forming a triangle), lobe “a” widely rounded. Left prehensile palp with finger very long compared to the trunk.

Description. Male: Greatest H slightly behind middle L. Dorsal margin, in lateral outline, almost evenly rounded (Figure 1 A), sloping towards anterior and posterior from indistinct middorsal angle, located somewhat posterior to midlenght. Anterior and posterior margins also evenly rounded and equally wide. Ventral margin almost straight. LV overlapping RV dorsally, anteriorly and posteriorly. LV also with well developed posterodorsal flange. In dorsal view, both ends slightly pointed and equally wide, posterodorsal flange on LV visible as a keel, extension of LV overlapping corresponding posterodorsal part of RV (Figure 1 B). Inner calcified lamella narrow: anteriorly 9 percent, posteriorly 5 percent of total L. Marginal pore canals straight, short and more dense anteriorly. Surface of carapace smooth, covered with sparse and short setae. Salvage not present on either valve. Hinge adont.

A1 (Figure 2 C): 7-segmented. First segment with 4 setae. All segments free (i.e. no fusion between segments). Second and third segments with one anterior seta each, fourth and fifth segments with two anterior and one posterior seta each (anterior ones being long, posterior short). Penultimate segment with two posterior and two anterior setae (only most posterior seta being short). Alpha seta not observed. Terminal segment with three setae and aesthetasc ya, which 1.7 times longer than terminal segment. L ratios of endopodal segments 1.2: 1.2: 1: 1: 1.3: 1.3.

A2 (Figure 2 D): 6-segmented (first one not drawn). Penultimate segment subdivided (second and third endopodal segments of male A2 homologous to second segment of female antenna) with two t-setae transformed into male sexual bristles. Exopod with one long and two short setae. Seta t1 very long and plumed (well exceeding distal end of terminal segment). Claw G2 as long as first endopodal segment. Claw G1 reduced and half as long as G2, G3 seta-like and as long as G1. Seta z1 short and reaching 2/3 of G1, z2 transformed into claw, as long as G2; z3 seta not reaching distal end of terminal segment. Terminal segment with long Gm claw, and short GM claw, one additional thin claw and sensory seta, and one thin seta. Aesthetasc Y half as long as first endopodal segment; setae y1, y2 and y3 all relatively short. L ratios between endopodal segments 4.3: 2: 1.3: 1.

Md (Figure 3 E): palp 4-segmented. First segment with one short smooth seta, one short plumed seta, and two long, plumed setae. Second segment with one exterior seta, reaching distal end of penultimate segment. Inner edge of same segment with group of 3+2 setae (three long and one short seta situated laterally; one long situated distally on segment). Penultimate segment with three exterior distal setae, three interior distal setae, and two posterior distal setae. Terminal segment short, only about 1.5 times longer than wide, with one central claw, one exterior claw and two interior setae.

Rake-like organ (Figure 1 D): with about 15 unequal small teeth.

Mxl (Figure 1 E): Palp 2-segmented. First segment with four plumed setae. Second segment with two prominent claws and four seta/claws.

Prehensile palps (Figure 1 C): with very elongated fingers and prominent subterminal setae. Palps almost symmetrical.

T2 (Figure 2 A): 5-segmented. Basal segment with one seta (d1), first and second endopodal segments with one seta each. Penultimate segment with two setae. Terminal claw (h2) 0.9 times as long as three terminal segments combined, seta h1 half as long as terminal segment, seta h3 as long as same segment.

T3 (Figure1 G): 5-segmented. Basal segment with three setae, first, second and third segments with one seta each. Terminal segment with three setae, h1 being the shortest, half as long as h2, which is half as long as h3.

CR (Figure 1 F): without posterior seta, with a group of tiny setules posteriorly, near base of posterior claw. L ratios between anterior margin, anterior and posterior claw 1.5: 1: 1. Anterior seta very short.

Attachment of CR (Figure 1 H): with only one lateral branch.

Hemipenis (Figure 2 B): Lobe “a” quadrate, lobe “b” with sinusoid distal margin; part “g” (middle peace) short. Ejaculatory process (“e”) barely distinguishable.

Dimensions: L of carapace 0.84 mm, greatest H equaling 46 percent of L.

Female: Shape very similar to that of male (Figure 3 A).

Antenna (Figure 3 B): All t setae present and well-developed. One seta present extero-medially on penultimate segment. Claw G2 as long as G1 and G3. Seta z1 slightly stronger than other two z setae, all only exceeding distal end of terminal segment. L ratios of three endopodal segments equaling 5.2: 3.7: 1.

T1 (Figure 3 C): both a and a’ setae present, b and d seta also present. Three rays in exopod and approximately 10 setae on masticatory process.

CR and genital segment (Figure 3 D): L ratio between anterior margin, anterior and posterior claws equaling 1.3: 1: 1. Genital lobe with small triangular extension, visible only in lateral view on intact animals (arrow in Figure 3 A), not visible on slide (Figure 3 D).

Dimensions: L of carapace 0.83 mm. Greatest H equaling 47 percent of L (same in female paratype).

Other appendages similar to those in male.

Remarks and affinities. Latinopsis patagonica sp. nov. is most closely related to L. falclandica comb. nov. They share a similar carapace appearance. They differ in the shape of the lobe “b” of the hemipenis, which has a sinusoid distal margin but rounded ventral margin in L. falclandica, while ventral margin is pointed (forming a triangle) in L. patagonica; lobe “a” is also more widely rounded in L. patagonica. There is also a difference in the appearance of the left prehensile palp: the finger is much longer compared to the trunk in L. patagonica than in L. falclandica. In addition, Vávra (1898) did not mention anything regarding a prominent posterodorsal flange on the left valve of L. falclandica, which is present in L. patagonica. Latinopsis patagonica is also related to the species Tressler (19341) reported as Candonopsis kingsleii from which it differs by a larger lobe “b”, more widely rounded lobe “a” and longer subterminal setae on the prehensile palps. Latinopsis columbiensis has a completely different appearance of the lobe “b” and much shorter finger on the prehensile palps. Carapace of L. anisitsi has a flat dorsal margin, and the hemipenis has a more triangular lobe “a” and a less developed lobe “b”.