Loxocauda orientalis Schornikov, 2011

Yoo, Hyunsu, Huyen, Pham Thi Minh, Chae, Jinho & Karanovic, Ivana, 2023, Three Loxocaudinae species (Ostracoda, Podocopida) from South Korea, ZooKeys 1138, pp. 183-209 : 183

Loxocauda orientalis Schornikov, 2011

Figs 9 , 10

Loxocauda sp. - Schornikov 2006: 43; Zenina 2009: 307.

Loxocauda sp. 6 - Lee et al. 2000: 465.

Loxocauda sp. 9 - Lee et al. 2000: 466.

Loxocauda orientalis Schornikov, 2011: 100.

Material examined.

One male, dissected on one slide and shell on micropaleontological slide from South Korea, Gyeongsangnam-do, Geoje-si, Geoje-myeon , Beopdongeogu-ro , Beopdong harbor. 34°49.252'N, 128°31.227'E, 5 Apr 2021, leg. Changgyun Yu & Byung-jin Yoo ; two females, dissected on one slide each, and one male dissected on one slide, all shells on separate micropaleontological slides from South Korea, Jeollabuk-do, Buan-gun, Byeonsan-myeon, Saemangeum-ro , Garyuk-do harbor. 35°43.603'N, 126°31.770'E, 30 Apr 2021, leg. Hyunsu Yoo & Byung-jin Yoo.

Redescription.

Male. Carapace (Figs 9A , 10 ). Larger than another Glacioloxoconcha species, L ~ 420 µm, H ~ 243 µm. RV overlapping LV dorsally. Carapace subquadrate in lateral view (Figs 9A , 10A, B ). Anterior margin rounded, dorsal margin slightly arched and postero-dorsal margin with caudal process smaller than in G. jeongokensis sp. nov. (size almost 50 µm), ventral margin straight, postero-ventral margin with spine (Fig. 10E ). Postero-ventral and anterior margins strongly compressed. Greatest H situated in front of middle. Surface smooth with few simple setae sporadically distributed (Fig. 10A ). Marginal pore canals strongly developed and distributed from anterior to posterior margins (Fig. 9A ). Fused zone situated medially on ventral margin, strongly developed. Muscular scar imprints consisting of a row of four vertical scars, one bent frontal scar, with two scars below it (Fig. 10F ). Hinge adont (Fig. 9A ).

A1 (Fig. 9B ). Six-segmented. First segment without setulae and setae. Second segment with setulae on antero-distal and one bare seta on postero-distal margin, reaching 1/3 length of fourth segment. Third segment with one bare seta on antero-distally, reaching 3/4 length of fourth segment. Fourth segment with two bare setae, one antero-distally, reaching 1/2 length of next segment, another postero-distally, reaching 3/4 length of next segment. Penultimate segment with four bare setae, three setae antero-distally, and one on postero-distal margin, length of two setae on anteriorly reaching slightly over terminal segment, and one reaching 2/3 length of terminal segment, length of one seta on posteriorly over terminal segment. Terminal segment with three long, bare setae on distal margin, almost 1.5 × longer than terminal segment. L ratios between six segments 1.7: 1.3: 1: 1.2: 1.5: 1.6.

A2 (Fig. 9C ). Four-segmented. Exopod transformed into two-segmented spinneret seta. First endopodal segment without setulae or seta. Second segment with one bare seta postero-distally reaching 2/3 of following segment. Third segment with setulae antero-proximally, and with one bare seta on antero-proximal margin, reaching 1/2 length of the same segment; two bare setae postero-medially, reaching 2/3 length of same segment, one bare seta postero-distally, almost 2.5 × longer than terminal segment, one bare seta on distal margin, almost 4 × longer than terminal segment. Terminal segment with one strong, bare claw on distal margin almost 4 × longer than same segment. L ratios between four segments: 7.1: 3: 11.4: 1.

Hp (Fig. 9E ). Basal plate subquadrate with flection antero-medially, four bare setae antero-distally, and strong muscle keeping tension between central and peripheral parts. Distal lobe sub-triangular. Ejaculatory process densely coiled.

Female. Larger than males. L ~ 484 µm, H ~ 287 µm. Shape and all other morphological features similar to male. Fused zone with three simple setulae.

GF (Fig. 9D ). Basal plate sub-rectangular and Ovary subquadrate. Without setulae and setae.

Figures

Figure 9. Loxocauda orientalis Schornikov, 2011: male A RV internal view B A 1 C A 2; female D GF; male E Hp. Scale bars: 50 µm (B, C, D, E); 100 µm (A).

Figure 10. SEM photographs of Loxocauda orientalis Schornikov, 2011: male A LV external view B RV internal view; male C dorsal view D posterior part of dorsal margin E postero-ventral margin (black arrow point to spines) F muscular scar print.