Kaloketos pilosus, a new genus and species of Remipedia (Crustacea) from the Turks and Caicos Islands Author Koenemann, Stefan Author Iliffe, Thomas M. Author Yager, Jill text Zootaxa 2004 618 1 12 journal article 10.5281/zenodo.158346 1dab7fa0-0a69-4071-8548-ca0bed8b74e7 1175­5326 158346 90B4753E-8947-4452-9930-E76FDA95A910 Kaloketos pilosus new species ( Figs. 1–5 ) Type locality . Cottage Pond, North Caicos Island , Turks and Caicos Islands ( 21º 56’ N , 72º 00’ W ). Material examined . Holotype , deposited in Zoological Museum Amsterdam ( ZMA .Rem.204641; partly mounted on SEM stub), 29 mm , 41 trunk segments, collected by T. Iliffe, 10 June 2003 , in 25–46 m depth of anchialine cave below halocline; 1 paratype , retained in research collection of Jill Yager, 26.5 mm , 40 trunk segments, collected by Dennis Williams, 20 October 1983 . Etymology . The epithet pilosus (Latin for hairy, covered with hair) refers to the dense fields of short spines and setae on the limbs of this species. Diagnosis . A medium­sized species of robust build, up to 29 mm long, composed of 40–41 trunk segments ( Fig. 1 ). First trunk segment small, completely covered by head shield; sternal bars heteromorphic (as enlarged convex flap on trunk segment 14, all remaining bars with concave distal margins; Fig. 2 A). Dorsal flagella of antennules very long, reaching over 50% of body length, composed of 18 segments; ventral flagellum with up to 18 segments ( Figs. 1 ; 3A). All remaining diagnostic characters as described for the genus. Description . Based on holotype and paratype . Body robust and long, length ca. 29 mm , with 41 trunk segments (see Fig. 1 ). Pleurotergites well developed, with broadly rounded distolateral corners on trunk segments 2–11, becoming more acuminate posteriorly ( Fig. 2 A). Trunk sternites with pointed posterolateral corners; sternal bars heteromorphic, as convex flap on segment 14, and with concave distal margins on remaining segments anterior and posterior to segment 14 ( Fig. 2 A). Female gonopores (on trunk segment 7) small; male gonopores (on trunk segment 14) large, cylindrical. Head shield subquadrangular; first trunk segment small and narrow, completely covered by head shield ( Figs. 1 ; 2A). Frontal filaments with short mid­medial processes ( Fig. 3 C). Antennules ( Figs. 1 ; 3A): Peduncle slightly dilated ventrally, bearing dense rows of very fine aesthetascs. Dorsal flagellum long, reaching 55–60% of length of body, composed of 18 segments. Ventral flagellum with 17–18 segments, slightly longer than head shield, 40–45% of length of dorsal flagellum, articulation of proximal segments weak. Both flagella with small, short setae. FIGURE 1. Kaloketos pilosus n. gen. , n. sp. Photo of 29 mm holotype. Antennae ( Fig. 3 B): Protopod 2­segmented; proximal segment with ca. 13 setae, distal segment with 13–18 setae (in two rows). Exopod wider and more than twice as long as adjacent distal segment of protopod, equipped with more than 60 long setae. Endopod bent in a semicircular way; first (proximal) segment with 14–16 setae; second segment with double row of setae; distal segment with double row of setae on lateral (anterior) and distal margins, and single row of setae on medial margin. All setae plumose (or 'faintly feathered'; cf. Fig. 2 E). Labrum fleshy, with posterolateral margins bearing three disjunct clusters of fine setules ( Fig. 3 D). Mandibles: Both right incisor process and lacinia mobilis equipped with three large denticles each ( Fig. 3 E). Left incisor process with four large denticles; left lacinia mobilis crescent­shaped, bearing several large and small denticles ( Fig. 3 F). Molar processes prominent; distal surface long and narrow, bearing dense rows of fine, plumose setae on outer margins. Maxillules ( Fig. 4 A, E): Segment 1 with long and narrow endite, bearing 1 prominent, apical spine and 9–10 smaller subapical spines (all spines naked). Segment 2 with broad, spatulate endite; medial (proximal) margin with regular row of 7 short, naked spines; lateral (distal) margin with row of long setae; apical margin bearing 1–2 finely serrate spines (between row of long setae and row of short spines; Fig. 4 E); anterior surface with several long, finely serrate setae and short, feathered setae ( Fig. 5 C). Segment 3 short; endite with rounded apical margin, bearing about 10 long setae, and 2 long, slender, finely serrate apical spines (cf. Fig. 4 E). Segment 4 with expanded, oblique enditic margin, bearing 2 long, slender, finely serrate spines on apical margin, and two rows of long and short, finely serrate subapical setae (cf. Fig. 4 E). Segment 5 slightly shorter and narrower than fourth segment, with rows of few naked setae on distal margins. Segment 6 short, with separate rows of naked setae on distal margins. Claw long and well developed. FIGURE 2. Kaloketos pilosus n. sp. , 29 mm holotype. A, above: dorsal view of head shield with anterior trunk segments 2–4; below: ventral view of three trunk segments, with sternites and sternal bars of segments 6, 14 and 15, respectively (scale bar for sternites 6, 14 and 15 = 1 mm). B, 14th thoracopod, with enlarged detail of spine row on expanded margin of endopod (x, serrate spine; y, setulose spine). C, second thoracopod. D, thoracopod from posterior trunk near abdominal somite. E, plumose seta. F, anal segment and caudal rami (scale bar = 0.5 mm). Scale bar B–D = 1 mm. FIGURE 3. Kaloketos pilosus n. sp. , 29 mm holotype. A, antennule (scale bar = 1 mm). B, antenna. C, frontal filaments. D, labrum (scale bar = 0.5 mm). E, right mandible. F, enlarged lacinia mobilis and incisor process of left mandible. Scale bar B, C, E = 0.5 mm. Maxillae ( Figs. 4 B; 5): Endites of segment 1 bearing 1 prominent, apical spine accompanied by several short spines and rows of long and short, finely serrate setae on both margins. Segment 2 with broadly rounded endite, bearing a row of short spines on proximal margin, and a double row of finely serrate setae on distal margin. Segment 3 pear­shaped, distinctly expanded, with 2 rows of short, feathered setae and a few finely serrate setae on medial margin. Segments 4–6 weakly expanded, growing gradually shorter in length from proximal to distal, medial margins densely covered with short feathered setae ( Fig. 5 A, C), and a few distal setae; segment 4 slightly shorter than third segment. Arc of horseshoetype claw finely serrate, composed of 17–19 fine denticles flanked by stouter, more separate denticles on each side ( Figs. 4 D; 5B). FIGURE 4. Kaloketos pilosus n. sp. , 29 mm holotype. A, maxillule. B, maxilla. C, maxilliped. D, claw of maxilla. E, finely serrate spine of segment 2, and segments 3–4 of maxillule. Roman numerals indicate individual limb segments; scale bar = 1 mm. Maxillipeds distinctly larger than maxillae, slender, 9­segmented ( Fig. 4 C); elbow between segments 4 and 5. Proximal segments 1–3 with oblique, interconnected articulation; segments 1 and 2 bearing a few short medial setae; segment 3 broadly rounded, bearing a few naked setae and a dense cover of short, feathered setae on distal and proximal margins. Fourth segment elongate, with expanded, oblique medial margin densely covered with short, feathered setae and a few naked setae. Segment 5 shorter than segment 4, distal margin weakly expanded. Segments 5–8 gradually decreasing in length; medial margins densely covered with short, feathered setae and a few naked setae (cf. Fig. 5 A, C). Claw similar to that of maxillae ( Figs. 4 D; 5B). Trunk appendages ( Fig. 2 B–E): Larger limbs of anterior to mid­trunk region stout, with expanded endo­ and exopods; limbs of anterior­most and posterior trunk smaller and narrower ( Fig. 2 C, D). Basal segment of four­segmented endopod with row of short setulose spines on distal margin; segment 2 distinctly expanded, much wider than long, bearing up to 14 short serrate spines on distolateral margin and up to 32 short, mostly setulose spines on distomedial margin (intermingled with a few serrate spines at distal end of row; Fig. 2 B­x+y); segment 3 bearing up to 17 setae and up to 12–14 serrate spines on lateral and medial margins, respectively; segment 4 ovate, with long, plumose setae. First segment of 3­segmented exopod bearing long setae on lateral margin, and a row of up to ca. 21 short serrate spines on distolateral corner; segment 2 subquadrangular, with setae on both lateral and medial margins, and up to 19 serrate spines distolateral corner; segment 3 ovate, with long, marginal setae. All setae plumose ( Fig. 2 E). Anal segment slightly wider than long ( Fig 2 F); caudal rami about 20% longer than anal somite, with a few short setae on proximomedial margins and about 18 longer setae on apical margins.