Ostracoda (Myodocopa) from Anchialine Caves and Ocean Blue Holes Author Kornicker, Louis S. Author Iliffe, Thomas M. Author Harrison-Nelson, Elizabeth text Zootaxa 2007 2007-08-31 1565 1 1 151 https://biotaxa.org/Zootaxa/article/view/zootaxa.1565.1.1 journal article 10.11646/zootaxa.1565.1.1 1175­5334 5095810 A2CDD9CB-CA5E-418B-A471-9EEFDC5CCF16 Rutiderma flex , new species Figs. 48–51 Etymology. An arbitrary combination of letters. Holotype . USNM 1021462 , adult male on slide and in alcohol. Type locality. Conch Sound Blue Hole, Andros Island, Great Bahama Bank. Paratypes . None. Distribution. Great Bahama Bank: Andros Island (Conch Sound Blue Hole). Description of adult male ( Figs. 48–51 ). Carapace with short rostrum and caudal process ( Fig. 48 ). Ornamentation: Carapace with alate posterior process well defined only along dorsal and posterior edges ( Figs. 48 , 49 b ). Surface with small round separated fossae ( Figs. 48 , 49c ). Single bristles present along valve margins and widely scattered on lateral surface ( Figs. 48 , 49 c ). Anterior margin of rostrum with scalloped edge. Tip of caudal process with minute indentation ( Figs. 48 , 49 b,d,f,g ). Infold: Infold of rostrum with 7 single bristles ( Fig. 49 c ). Anteroventral infold with 10 single bristles forming row ( Fig. 49 e ). Ventral infold anterior to caudal process with about 5 small single bristles forming row ( Fig. 49 d ). Infold of caudal process of each valve somewhat obscured by debris, with pocket with anterior oblique shelf with straight posterior edge without bristles ( Fig. 49 d,f ); ventral edge of shelf curves posteriorly and terminates in sclerotized process ( Fig. 49 d,f ); posterior edge of shelf with transparent lamellar prolongation; dorsal part of lamellar prolongation of right valve with minute serrations ( Fig. 49 d ); 3 or 4 small bristles present near posterior edge of caudal process ( Fig. 49 d,f ). Lamellar prolongation may be divided at incisure, but obscured by debris. Central adductor muscle attachments ( Figs. 48 , 49 a,g ): Consisting of about 19 ovoid attachments. Carapace size (length, height in mm): USNM 1021462, 1.21, 0.73. First antenna ( Figs. 49 g , 50 a,l ): 1st segment bare. 2nd segment with proximal dorsal spines, a few distal ventral spines, many faint lateral spines in distal dorsal corner, 1 dorsal bristle, and 1 distal lateral bristle. 3rd segment short, dorsal margin longer than ventral margin, with 3 bristles (1 ventral, 2 dorsal). 4th segment with 4 bristles (3 ventral, 1 dorsal). 5th segment small, inserted ventrally between 4th and 6th segments, with stout cylindrical proximal part and 1 stout terminal bristle and many slender terminal filaments (at least 25, only 4 shown). 6th segment with 1 distal dorsal bristle. 7th segment with short a-bristle, stout b-bristle with 2 filaments, and long c-bristle with about 10 filaments. 8th segment with bare filamentous d- and e-bristles, long fbristle with about 11 filaments, and stout g-bristle with 1 or 2 filaments. Both c- and f-bristles almost as long as carapace ( Fig. 49 g ). Second antenna: Protopod bare ( Fig. 50 b,c,l ). Endopod with 3 segments ( Fig. 50 b,c ): 1st segment short with 5 bristles (4 proximal, 1 distal); 2nd segment elongate with 2 separated bristles just distal to midlength; 3rd segment elongate and reflexed with 1 proximal and 2 terminal bristles. Exopod with 9 segments ( Fig. 50 d ): 1st segment with 2 or 3 distal ventral spines ( Fig. 50 d ) and minute terminal medial spine ( Fig. 50 d,e ); 2nd segment short with bare ventral bristle almost reaching 5th segment; segments 3–8 with long ventral bristle with natatory hairs; 9th segment with 5 bristles (4 with natatory hairs (dorsal bristle one-half length of others), 1 medial near dorsal margin, minute, bare) ( Fig. 50d ). Mandible ( Figs. 48 , 50 f ): Coxa endite represented by 2 minute spines at midheight. Basis: medial surface with 4 proximal bristles (2 medium length, 2 minute) near ventral margin; dorsal margin with 3 bristles (1 near midlength, 2 distal longer). Exopodite: lateral near dorsal margin, elongate, about one-half length dorsal margin of 1st endopod segment, with terminal spines. Endopod: 1st segment short with 2 ventral bristles. 2nd segment elongate, with ventral and medial spines, 3 dorsal bristles, and 6 short distal bristles (2 a-bristles, 1 bbristle, 1 c-bristle, 2 d-bristles). 3rd segment with 5 bristles (3 short a-bristles, 1 longer b-bristle, and 1 very long claw-like c-bristle). Maxilla ( Fig. 50 g ): Limb reduced. Bristles somewhat obscured on limb examined under oil immersion lens. Coxa with plumose dorsal bristle. Basis with bristle near dorsal margin and 2 at midwidth. Endites I–III with total of about 11 bristles. Endopod 2nd segment with about 7 weakly developed bristles. Exopod not observed. Fifth limb ( Fig. 50 h ): Segmentation unclear. Endopod 2nd segment with 5 ringed bristles. Exopod with 2 distinct ringed bristles. Epipod with about 30 plumose bristles. FIGURE 48. Rutiderma flex , new species , holotype USNM 1021462, adult male; complete specimen from left side, length 1.21 mm. FIGURE 49. Rutiderma flex , new species , paratype USNM 1021462, adult male: a, central adductor muscle scars of left valve, ov; b, posterior right valve, ov; c, anterior right valve, iv; d, posterior right valve, iv; e, anteroventral margin of right valve, iv; f, posterior left valve, iv; g, specimen with right valve removed showing ends of central adductor muscles, outline of right lateral eye, and right first antenna, lv (nabs). Scale equals 0.10 mm ( a–f ) and 0.20 mm ( g) . Sixth limb ( Fig. 50 i ): Endite I with 2 bristles; endite II with 2 bristles; endite III with 3 bristles; endite IV with 3 bristles. End segment with 3 anterior bristles and 4 plumose posterior bristles along ventral edge; anterior bristles on small projection. 2 bristles in place of exopod. Posterior edge and medial surface of limb with hairs. Seventh limb ( Fig. 50 j ): Long, slender, with 3 or 4 proximal bristles (1 or 2 on each side), each with 2 bells, and 4 terminal bristles (2 on each side), each with 4 bells. Tip with opposing teeth, 2 on each side. Furca ( Figs. 48 , 51 b ): Each lamella with 4 primary claws followed by 1 or 2 secondary claws; claw 1 with medial and lateral row of teeth (distal teeth smaller); following claws with spines along posterior edge; claws 1 and 2 with proximal medial spines forming row; claws 1–3 with slender distal spines along anterior edge; right lamella anterior to left by width of base of claw 1. FIGURE 50. Rutiderma flex , new species , paratype USNM 1021462, adult male: a, right first antenna drawn on body, lv (nabs); b, part left second antenna, mv; c, endopod right second antenna, lv; d, exopod right second antenna, lv; e, articles 1 and 2 left second antenna, mv; f, right mandible drawn on body, lv; g, maxilla; h, right fifth limb drawn on body, lv; i, right sixth limb drawn on body, lv; j, left seventh limb; k, Bellonci Organ and medial eye; l, anterior of body from right side showing lateral eye and parts of first and second antenna. Scale equals 0.10 mm ( a–d,f,i–k,l ) and 0.05 mm ( e,g,h ). Bellonci Organ ( Fig. 50 k ): Elongate with proximal suture, short wide part near midlength, and pointed tip. Eyes: Medial eye with black pigment and without dorsal filaments ( Fig. 50 k ). Lateral eye about twice size of medial eye, with numerous divided ommatidia surrounded by black pigment except along edges ( Figs. 48 , 49 g , 50 l ). Upper lip ( Fig. 51 e ): Rounded bare. Copulatory limb ( Figs. 48 , 51 b–d ): Comprising 2 elongate lobes; tip of each lobe with minute sclerotized process and 2 pairs of small bristles. Posterior of body ( Fig. 51 a ): Bare. Girdle with ventral end fitting into small socket in dorsal margin of posterior end of Y-sclerite. Y-Sclerite ( Fig. 51 a,c ): Branching distally; posterior end forming angle. FIGURE 51. Rutiderma flex , new species , paratype USNM 1021462, adult male: posterior of body from right side showing Y-sclerite, girdle, and posterior end of furca; b, right lamella of furca and right copulatory organ; c, posterior of body from right side showing part right seventh limb; d, copulatory organs (right organ at left); e, upper lip from right side. Scale equals 0.10 mm ( a–e ). Comparisons. The carapace of the male R. flex differs from that of R. dinochelatum Kornicker 1958 ( Kornicker 1958 : fig. 46: 7a,b) in that the upper lateral rib does not extend anteriorly to intersect the anterior edge of the rostrum, and the lower lateral rib does not extend anteriorly to midlength of the carapace. The structure of the posterior edge of the shelf in the anterior part of the pocket of the infold of the caudal process of R. flex differs from those of R. darbyi Kornicker 1983 ( Kornicker 1983 : Fig. 23 b ) and R. schroederi Kornicker & Iliffe 2000 ( Kornicker & Iliffe 2000 : fig. 53 c,d (female)). The infold of the rostrum of R. flex bears a row of seven bristles compared to 12 on R. mortenseni Poulsen 1965 ( Poulsen 1965 : fig. 11 b ). The adult male of R. flex is larger than that of R. licinum Kornicker 1983 , the furca bears one or two instead of three secondary claws, and the basis of the mandible bears four instead of six bristles near the ventral margin.