Rugosuscandona scharfi, Külköylüoğlu & Akdemir & Yavuzatmaca & Schwartz & Hutchins, 2017

Külköylüoğlu, Okan, Akdemir, Derya, Yavuzatmaca, Mehmet, Schwartz, Benjamin F. & Hutchins, Benjamin T., 2017, Rugosuscandona, a New Genus of Candonidae (Crustacea: Ostracoda) from Groundwater Habitats in Texas, North America, Species Diversity 22, pp. 175-185 : 180-182

Rugosuscandona scharfi sp. nov.

( Figs 2–6 )

Material examined. Holotype: a male dissected with soft parts on one slide (OK-TX-AW016-008: 01). Collected from type locality on 07 March 2013 by Benjamin Hutchins and Benjamin Schwartz. Allotype: a female dissected with soft parts on one slide (OK-TX-AW016-008: 02). Collect- ed 25 February 2013 by Benjamin Hutchins and Benjamin Schwartz. All soft body parts of holotype and allotype dissected in lactophenol solution and sealed with translucent nail polish; valves kept in micropalaeontological cavity slides (OK-TX-AW016-008: 03, 04). Non-dissected paratypes (OK-TX-AW016-008: 05–13): total of 12 adults and 3 juveniles (2 adults, 26 February 2013; 2 adults + 1 juvenile, 27 February 2013; 1 adult, 28 February 2013; 1 adult, 4 March 2013; 2 adults, 6 March 2013; 1 juvenile, 21 March 2013; 2 adults + 1 juvenile, 25 March 2013; 1 adult +1 damaged adult individual, 27 March 2013) collected from the type locality by Benjamin Hutchins and Benjamin Schwartz , kept in 70% ethanol deposited at the Abant İzzet Baysal University, Department of Biology, Bolu Turkey .

Distribution. Known only from the type locality by Benjamin Hutchins and Benjamin Schwartz.

Description of male. Measurements (based on midlength): L= 0.53–0.65 mm, H= 0.25–0.30 mm, W= 0.14– 0.20 mm. Average: L= 0.62 mm, H= 0.28 mm, W= 0.18 mm (n =7).

LV overlaps RV from all sides ( Fig. 2A, C, D ). In lateral view, carapace subrectangular in shape, with elevated pore canal openings. Dorsal margin flat, LV almost rounded in all parts, RV slightly sloping posteriorly. Both margins equally rounded anteriorly. LV with flange (protrusion) posterodorsally in both sexes. Greatest height approximately at center. Valve surface ornamented with wrinkles forming almost hexagonal and/or pentagonal cells. Pore canals long with sensory setae on valve surface and dense around marginal zones of both valves in both sexes and juveniles ( Fig. 2H, I ). Muscle scars located closer to center but not visible on valve surface. Calcified inner lamella wide at both ends, outer lamella wide. In dorsal view, carapace narrow, hinge adont, both ends thin and almost blunt. In ventral view, valves slightly concave, LV strongly encompasses RV. Color translucent or opaque to pale white.

A1 ( Fig. 4A ) 6-segmented. First segment with 2 long smooth anterior and postero-distal setae; former reaching about end of second segment, latter extending almost to end of terminal segment. Wouter’s and Rome organs absent. Second segment with medium-sized smooth antero-medial seta reaching about to end of third segment. Both third and fourth segments without setae. Penultimate segment anterodorsally with 3 long setae subequal in length to all segments. Terminal segment with 3 subequally long setae and shorter ya aesthetasc.

A2 ( Fig. 4B ) 4-segmented including protopodite. First segment with smooth postero-distal seta reaching about end of penultimate segment. Exopod and exopodial setae not apparent: absent or rudimentary. Second segment with long L-shaped medio-ventral aesthetasc Y and long smooth seta, both extending to tips of terminal segment. y1 seta absent. Natatory (swimming) setae absent. Third (penultimate) segment without y2, z, or t setae. G2 and G3 claws slightly plumose and subequal in size. G1 claw absent. Mediumsized smooth antero-medial seta present on same segment. Terminal segment with GM and Gm claws and y3 aesthetasc. GM claw equal in size with G2 and G3 claws. Gm claw short, about 2/3 length of GM. Aesthetasc y3 longer than Gm by about 1/3 of its length.

Md ( Fig. 4D ) composed of coxa and Md-palp. Coxa well developed with 6+1 teeth and medium-sized smooth seta internally. Md-palp 4-segmented. First segment internally with slightly plumose S1 and S2. Alpha seta absent. Vibratory plate with 7+1 setae. Second segment with cluster of 3 equally long smooth setae internally. Beta seta short, about 1/3 length of S1 seta. Penultimate segment with 2 internodistal smooth setae exceeding length of terminal segment and externo-medial seta reaching to about middle of terminal claw. Short seta on penultimate segment present externo-distally, extending to about middle of terminal segment. Gamma seta not seen well. Terminal segment with fused and distally pappose claw, long and smooth external seta, and 2 setae internally (1 thin and small, another robust and slightly plumose). L ratios of 4 segments measured in middle 1.5: 1.1: 2: 1.

Mxl ( Fig. 4E ) composed of three endites and Mxl-palp. First and second endites bearing 6 and 5 short setae, respectively. Third endite with 2 long bristles and with 2 smooth short setae. Base of first endite with medium-sized plumos- ed seta. Mxl-palp 2-segmented. First segment with 3 smooth claw-like setae, second (terminal) segment subrectangular and short (L: W ratio 1.2: 1) with 3 long (2 smooth claw-like and 1 somewhat shorter), and 2 small setae. Vibratory plate with 13 plumose long setae.

Rake-like organ not observed.

Labium wide with 4+4 spine-like teeth on both sides ( Fig. 5E ).

T1 ( Fig. 6A, B ). Prehensile palps not divided, almost equal in size (left being slightly longer) and modified into clasping organs. Masticatory process comprising about half length of T1, ending with about 6+1 fine setae. Right palp with ventral projection with short spine-like claw and longer smooth claw. Same palp ending with short and thin claw. Left palp slightly longer and wider, without ventral projection. Only short d seta present, other setae (a, b, c setae) and vibratory plate not seen.

T2 ( Fig. 5A ) 5-segmented with plumose d1 seta on first segment (protopodite). Setae dp and d2 not observed. Next 3 segments (second, third and penultimate segments) with smooth and relatively short sub-apical seta (e, f, g) each, posteriorly. Terminal segment with very long, smooth claw (h2), extending about 2/3 length of second segment, and short external (h3) seta.

T3 ( Fig. 5B ) 4-segmented. First segment with medium d1 and longer d2 setae. Second segment without “e” seta. Penultimate segment not divided, f and g setae present. Terminal segment almost square and short with 3 setae (length: h3>h2>h1). L ratios of setae h1: h2: h3=1.1: 2.5: 6. Setae h1 and h2 slightly curved, seta h3 almost straight.

UR thin and with spine-like or rod-like claw with ramus. Other claws absent. Both anterior and posterior setae absent. Uropodal attachment slightly curved with branch.

Zenker’s organ ( Fig. 6C ) with 4+2 rings of spines ending with sperm canal.

Hemipenis ( Fig. 6D ) largest organ with well-developed subtriangular medial lobe “b”, small rounded distal lobe “h”, and lateral lobe “a” square in shape. M-process complex with distal part (g2) pointed. Sperm type helicoidalized, filamentous, and aflagellate ( Fig. 3D, E ).

Description of female. Carapace similar in shape but slightly longer than that of male ( Figs 2B, E–G , 3A ). Female L= 0.56–0.65 mm, H= 0.25–0.30 mm, W= 0.16–0.20 mm. Average: L= 0.63 mm, H=0.28, W= 0.182 mm (n =7). T1 normally developed, smaller than male clasping organs, with 3 relatively short subequal h1–3 setae ( Fig. 5C ) (h2>h3>h1). h2 seta twice long of h1. G claws (G1–G3, GM, Gm) present ( Figs 3B , 4C ). G2 claw shortest, about ½ long of G1 and G3 claws. GM claw long reaching tip of G1 claw and slightly longer than G3 claw (compare with male G1 absent, G2≈G3≈GM>Gm). All claws smooth. y3 longer than Gm claw. Uropod same to that of male with genital part large, rounded and without appendages ( Figs 3C , 5D ). All other soft parts same to that of male.

Etymology. The species is named after Dr Burkhard W. Scharf ( Germany) for his invaluable contribution to the ecology and taxonomy of the species of Ostracoda.

Figures

Fig. 2. SEM photographs of carapace of Rugosuscandona scharfi gen. nov. sp. nov. A, C, D, H, I: paratype (OK-TX-AW016-008: 05) male. B, E, F, G, J: paratype (OK-TX-AW016-008: 06) female. A) right side view, B) dorsal view, C) posterior end of right side, D) anterior end of right side, E) dorsal view of anterior margin, F) dorsal view of posterior margin, G) pore canals on dorsal side, H) central muscle scars, I) pore canals on anterior end, J) pore canals and surface ornamentation. Scale bars: 100µm for A, B; 10µm for C–J. Arrows indicate forward.

Fig. 3. SEM photographs of Rugosuscandona scharfi gen. nov. sp. nov. removed RV, paratype (OK-TX-AW016-008: 07) female. A) LV, interior view, B) right pair of A2, C) UR shown with thin arrow, D) sperm packs, E) close view of sperm packs. Scale bars: 100µm for A; 10µm for B–E. Arrows indicate forward.

Fig. 4. Rugosuscandona scharfi gen. nov. sp. nov. A, B, D, E: holotype male (OK-TX-AW016-008: 01), C: allotype female (OK-TX- AW016-008: 02). A) A1, B) A2, C) A2, D) Md, E) Mxl with vibratory plate.Scale bar: 100µm.

Fig. 5. Rugosuscandona scharfi gen. nov. sp. nov. A, B, E: holotype male (OK-TX-AW016-008: 01), C, D: allotype female (OK-TX- AW016-008: 02). A) T2, B) T3, C) T1, D) UR with genital organ and furcal attachment, E) labium. Scale bar: 100µm.

Fig. 6. Rugosuscandona scharfi gen. nov. sp. nov. holotype male (OK-TX-AW016-008: 01). A) left clasping organ, B) right clasping organ, C) Zenker’s organ, D) hemipenis. Scale bar: 100µm.