A new genus, Tuberocandona gen. nov. (Crustacea, Ostracoda, Candonidae) and past to present ostracod species diversity in Texas (USA) Author Kuelkoeylueoglu, Okan https://orcid.org/0000-0003-4712-5612 Department of Biology, Faculty of Arts and Science, Bolu Abant Izzet Baysal University, Bolu, 14300, Turkiye okankul@gmail.com Author Ataman, Alper https://orcid.org/0000-0003-2175-0137 Department of Biology, Faculty of Arts and Science, Bolu Abant Izzet Baysal University, Bolu, 14300, Turkiye Author Gibson, Randy https://orcid.org/0000-0001-9365-0819 Aquatic Resources Center, United States Fish and Wildlife Service, San Marcos, TX, USA Author Diaz, Peter Texas Fish and Wildlife Conservation Office, United States Fish and Wildlife Service, San Marcos, TX, USA text Subterranean Biology 2023 2023-03-21 45 119 140 http://dx.doi.org/10.3897/subtbiol.45.98075 journal article http://dx.doi.org/10.3897/subtbiol.45.98075 1314-2615-45-119 182285722C3943E1A8265C53ED1707A0 79ACCA69003F5982B871D57D4276BDAF Tuberocandona leonidasi sp. nov. Diagnosis. Holotype . Adult ♂ dissected in lactophenol solution with soft body parts (no: OK-TX-BCo-1) sealed with translucent nail polish; valve kept on a micropaleontological slide (no: OK-TX-BCo-2). Collected from the type locality on 4 and 9 of August 2021 by Peter Diaz. Allotype . Adult ♀ dissected in lactophenol solution with soft body parts from the type locality (no: OK-TX-BCo-3). Collected by Peter Diaz. Paratypes . Two ♂ (OK-TX-BCo-4) and two ♀ (OK-TX-BCo-5) mounted and sealed in glass slides, collected from the type locality; total of seven ♀ and four ♂ collected from type locality. Type locality. Perennial headwater of Honeycut Hollow Spring, Blanco County, Texas, USA (30.266319, -98.333497). Derivation of name. The species is named after the original landowner Caleb Leonidas Browning, Jr as per the current landowner's suggestion. Description. Male: Measurements (based on midlength). L=0.51-0.56 mm, H=0.24-0.27 mm, W=0.20-0.28 mm ( n =4). LV overlapping RV anteriorly and posteriorly (Fig. 2A, D-G ). Carapace elongate with two well-developed alae type tubercules or nodes on each valve, laterally. In dorsal view (Fig. 2E ), both margins pointed. Carapace surface ornamented and covered with spines, especially around each hexagonal cells, pore canals tubular with a thin seta (Fig. 2G ). Both margins with stiff spines (Fig. 2D ). Dorsal margin almost straight. Calcified inner lamella smooth, without inner list, wide in both margins. LV with internal node anteroventrally, RV smooth. Four large and one small central and two ventral muscle scars located about the center between the tubercles (Fig. 2F ). Eyes not visible. Antenulle (A1): Six segmented (Fig. 3A ): First segment (base) well-developed with a slightly plumosed long seta on dorsal margin, and two unequally long smooth setae on ventral margin. Second segment with a smooth dorsal-apical seta medium in size. Third and fourth segments without setae. Fifth segment with four long setae and one medium-sized antero-dorsal seta, and one very short ventral-apical seta. Terminal segment with three long and a medium-sized smooth aesthetasc ya (ca. 1/3 of long setae). Antenna (A2): Four segmented (Fig. 3B ). First segment with a long smooth dorsal-apical seta, reaching halfway of terminal segment. Exopod with one medium-sized and two very small exopodial setae. Second segment without natatory setae. Aesthetasc Y long with two segmented parts extending to end of subterminal segment, proximal part slightly longer than plumosed distal part. Anterior-dorsal seta smooth and long, anterior-dorsal seta very short (ca. 1/4 of subterminal segment). Penultimate segment with one short seta in dorsal margin, t-1 seta very short, t2 seta long 2 x terminal segment all smooth. t3-4 setae absent. Y2-seta not observed. G1 claw absent, G2 claw well developed, G3 claw very short and thin (ca. 2 x of terminal segment). Seta z-2 claw-like long reaching tips of G2 claw. Setae z1 and z3-4 not observed (cf. female A2). GM and Gm claws well-developed on terminal segment, Gm claw short about 3/4 of GM, and y3-seta very short and thin about size of terminal segment. All claws and z1-setae smooth. Mandible (Md) (Fig. 3C ): Coxa with seven robust teeth and thin short setae internally, and dorsal seta short and stout. Palp four segmented; first segment with vibratory plate bearing six plumosed setae, S1 and S2 setae plumosed and unequally long, alpha seta not observed. Second segment with a bunch of four long smooth setae, beta seta not observed. Two (one long and one medium sized) unequally long external setae extending to tips of terminal segment. Penultimate (third) segment with two equally long and smooth external setae, two internal setae unequally long and smooth, gamma seta medium-sized and slightly plumosed. Terminal segment slightly rectangular fused with one claw and one seta-like claw. L:W ratio of terminal segment 1.2. Maxillula (Mxl) (Fig. 3A ): With three small endites and a two-segmented palp, vibratory plate with 12-13 plumosed setae. First, second and third endites with five, five and six setae similar in size (two bristles smooth), respectively. Base of first endite with one long and slightly plumose seta. First segment of Mx-palp with 2 medial setae. First palp ca. 3 x longer than terminal (second) palp. Second segment squarish with 4 claw-like and smooth setae. Rake-like with 9-10 teeth (Fig. 3F ). First thoracic leg (T1) (Fig. 3G, H ): Palps well developed and asymmetrical ending with hooked-like fingers modified into clasping organs. Right palp (Fig. 3G ) stronger and robust. Left palp (Fig. 3H ) slightly longer than right one. Both fingers ending with a well-developed spine, and two claws. Endite (masticatory process) with 9 to 10 smooth long setae (thicker than usually known). Two unequally long "a" and one "d" seta present, setae "b" and "c" not observed. Vibratory plate with one smooth short seta. Second thoracic leg (T2) (Fig. 4B ): Five segmented with a medium-sized slightly plumose d1 seta on the first segment. Second without seta. Third and fourth segments with unequally long f and g setae, respectively. Terminal segment subrectangular, seta h1 reduced or absent, h2 claw smooth and well-developed, longer than the last three segments. Seta h3 thin. Third thoracic leg (T3) (Fig. 4C ): Five segmented with a well-developed slightly plumose d1, setae d2 and dp absent. Second segment without seta e. Third and fourth segments with smooth "f" and "g" setae, respectively. Terminal segment square three h setae as seen in the Figure. Uropod (Fig. 4D ): Well developed ramus with anterior and posterior claws. Anterior seta short and spine-like, posterior seta absent. Both claws curved and slightly serrated anteriorly. Caudal attachment with one branch. Hemipenis (Fig. 4E ): Large and robust, outer lobe "a" rounded, inner lobe "b" small, medial lobe "h" large and slightly pointing. Zenker organ (Fig. 4F ): With five whorls ending with 15-16 sperm canal. Color : Translucent to opaque white. Description of female. Carapace similar in shape of male (Fig. 2B, C ). Measurements: L=0.55 mm, H=0.25 mm, W=0.25 mm ( n =2). G-claws (length ratio G1≈G3≈GM>Gm>G2) (G2 ca. 1/3 of G1) present on A2 (Fig. 3E ). Setae z1-2 thin and very short slightly extending terminal segment, setae z3-4 not observed. Long seta on exopod reaching halfway of subterminal segment (cf. male exopod). Two unequally long and smooth setae present on basal segment (cf. male A2). T1 (Fig. 4A ) normally developed, endopod with 2 short (h1, h3) setae, h2 seta not observed. All smooth. Endite with 8-10 apical setae, slightly transformed to claw like. Genital part (Fig. 4G ) rounded with a robust genital hook inside. All other parts similar to the males. Accompanying taxa. Comalcandona tressleri Kuelkoeylueoglu and Gibson, and Neglecandona cf. neglecta (Sars, 1887).