Ancylomenes speciosus

Ancylomenes speciosus (Okuno, 2004) (Figs. 1–12) Synonymy. Periclimenes speciosus Okuno, 2004: 866 (full synonymy, description), Figs. 1–5, 6A–B [type locality: Hira-ne, Hasama, Tateyama, Boso Peninsula, Honshu, Japan, 34°58.6’N 139°47.1’E, 18 m]. Ancylomenes speciosus. — Okuno and Bruce, 2010: 88 (key), 98 (discussion), 100.— Minemizu, 2013: 82, two upper unnumbered photos.— Saito, 2015: 67–73, Fig. 3.— Horká et al., 2016: Suppl. Table S1 (DNA dataset).— Horká et al., 2018: Table 1 (DNA dataset), 78. ? Ancylomenes speciosus. — Bruce, 2011: 67 (discuss.) Material.— Japan: 1 ovigerous female, paratype, pocl 5.5 mm, RMNH D.50660, Nagasaki, Kyushu, depth 15 m, 13 Sep. 2003, collected by J. Okuno. — Taiwan: 1 male, pocl 2.7 mm, NMMBCD5629, Hojie, Pingtung County, associated with sea anemone, depth 26–29 m, 7 Mar. 2015, collected by C.-W. Lin [fcn 20150307-16]. — 1 male, pocl 3.5 mm, NMMBCD5630, Hojie, Pingtung County, 7 Mar. 2015, collected by C.-W. Lin [fcn 0120225-06]. — 1 ovigerous female, pocl 4.5 mm, NMMBCD5631, Hojie, Pingtung County, 19 Apr. 2013, collected by C.-W. Lin [fcn 20130419-18]. — 1 ovigerous female, pocl 4.5 mm, NMMBCD5632, Hojie, Pingtung County, 9 Oct. 2015, collected by C.-W. Lin [fcn 20151009-nn]. — 1 female, pocl 4.1 mm, NMMBCD5634, Hojie, Pingtung County, 2 May 2023, collected by C.-W. Lin [fcn 20230502-nn]. — New Caledonia: 1 ovigerous female, pocl 4.6 mm, MNHN-IU- 2018- 1358, KOUMAC 2.1, KR644, Passe du Baron, off Koumac, New Caledonia, 20°33.8’S, 164°10.3’E, 29 Sep. 2018, host unknown, leg. Z. Ďuriš & A. Šobáňová. —1 damaged juvenile / subadult male, pocl 1.8 mm, MNHN-IU-2018- 728, KOUMAC 2.1, KR212, lagoon, between Ilôt Rat and Récif de l’Infernet, off Koumac, New Caledonia, 20°34.9’S, 164°12.6’E, 11 Sep. 2018, from carpet sea anemone on sandy bottom, collected by Marina Poddubetskaya, leg. Z. Ďuriš & A. Šobáňová. — Great Barrier Reef, Australia: 1 juvenile female, pocl 1.5 mm, MTQ W.33108, CReefs 2010, LI10011, 14° 41.4’S, 145° 27.9’E, 26 Aug. 2010, Channel bommies, Lizard Island, from Heteractis sp., depth 12.6 m; collected by Z. Ďuriš [fcn UO.26- Au 10]. Description (ovigerous female, New Caledonia, MNHN-IU-2018-1358). Medium sized palaemonid shrimp of subcylindrical body form (Figs. 1−3). Carapace (Figs. 3, 4 A−C) smooth; orbit feebly developed, inferior orbital angle strongly produced, acute, with reflected ventral inner flange; antennal tooth well developed, slender, submarginal, arising with distinct interval from inferior orbital angle; hepatic tooth large, arising slightly ventral to level of antennal tooth; dorsal median carina armed with single postrostral tooth; supraorbital tooth absent; pterygostomial angle blunt. Rostrum (Fig. 4 A−C) slender, almost straight, 0.8 times as long as carapace, overreaching distal margin of intermediate segment of antennular peduncle; dorsal margin armed with 8 equidistant, acute, anteriorly directed teeth interspaced by short plumose setae; ventral margin with carina obsolete, fringed with row of long plumose setae, subterminally armed with 3 small, acute teeth; lateral carina obsolete. Pleon (Fig. 3) smooth; first to fifth pleurae posteroventrally rounded, second pleuron roundly expanded anteriorly, first to third pleuron each with rounded ventral membranous lobe; posteroventral margin of fourth and fifth pleuron produced, rounded. Posterior third of median carina of third tergum moderately elevated and compressed. Sixth somite elongate, dorsal margin subequal to pocl, 1.2 times as long as telson, posterolateral and posteroventral angles produced, acute. Telson (Fig. 4D, E) 0.8 times as long as pocl, gradually tapering posteriorly to posterior margin with midpoint convex; dorsal surface armed with 2 pairs of small submarginal spinules of about 0.07 of telson length, situated at 0.55 and 0.8 of telson length; posterior margin with 3 pairs of spines, lateral spines short, subequal to dorsal spinules, intermediate spines about 3 times longer than lateral; submedian spines plumose, half-length of intermediate spines. Ophthalmic somite with interocular process small, subacute (Fig. 4A, B). Eye (Fig. 4B, C) with large, globular cornea, minute accessory pigment spot present dorsally on posterior corneal margin; stalk slightly longer than corneal diameter, slightly swollen basally, narrowing distally. Soft basal eye peduncle with collar-like sclerotized lateral lobe overlapping orbital margin of carapace (Fig. 4B). Fourth thoracic sternite unarmed. Antennular peduncle (Fig. 4A, C) reaching level of distolateral tooth of scaphocerite. Basal segment mediodorsal margin as long as distal two segments combined; distal part of lateral margin straight terminating with small acute tooth, anterolateral margin broadly rounded, reaching midlength of intermediate segment, with row of plumose setae; ventromesial margin armed with small acute tooth just ahead of statocyst; stylocerite short, elongately triangular, tapering to acute tip, falling short of half-length of proximal segment (distolateral lobe excluded); statocyst well developed, rounded. Intermediate segment slender, about half of length of proximal segment, medially with long plumose setae. Distal segment slender, subequal to preceding one, non-setose, articulated with flagella. Upper flagellum biramous, proximal 8 segments fused, shorter free ramus consisting of 4 segments; about 20 groups of long aesthetascs present on fused rami (starting from 4 th segment) and shorter free ramus. Antenna (Fig. 4 A−C) with stout basicerite (Fig. 4B) armed ventrolaterally with acute tooth, dorsal margin with rounded proximal process. Scaphocerite well developed, 2.7 times as long as maximum width, lateral margin almost straight, terminating in acute tooth distinctly falling short of distal margin of subquadrate lamella; carpocerite falling short of midlength of scaphocerite. Epistome unarmed. Paragnaths (Fig. 5A) subdivided distally by narrow deep median incision, two convex submedian ridges proximally on fused basis; alae laterally produced, with bilobed lateral margins. Mandible (Fig. 5B, C) moderately robust, without palp; molar process obliquely truncate distally, with blunt teeth and small field of a few short setae; incisor process obliquely truncate distally, with 4 acute distal teeth. Maxillula (Fig. 5D) with bilobed palp, lower lobe bearing small hooked seta; upper lacinia strongly convex on dorsal margin, broadened in middle, distal margin truncate, with about 10 simple spines, with several distoventral setae; lower lacinia narrower than upper lacinia, tapering to rounded distal margin, with numerous setae along margins of distal half of length. Maxilla (Fig. 5E) with simple palp tapering distally; distal endite deeply bilobed, lobes slender, distally rounded, upper lobe broader than lower lobe, terminally with dense long setae; proximal endite obsolete; scaphognathite well developed, with dense plumose setae marginally, anterior lobe twice overreaching palp, tapering slightly distally, rounded, posterior lobe distally subquadrate. First maxilliped (Fig. 5F) with slender tapering palp; distal endite broad, distal margin broadly rounded, falling short of palp apex, with long setae, mesial margin densely setose; proximal endite obsolete; exopod with caridean lobe well developed, low laterally, with rounded distal margin overreaching palp, flagellum well developed, elongate, compressed, terminally with 4 long plumose setae and 2 short subapical plumose setae; epipod robust, subtriangular, with angles rounded. Second maxilliped (Fig. 5G) of normal shape; coxa produced medially, with several long setae; endopod with ischium and basis fused, suture feebly demarcated, mesial surface slightly concave, with elongate depression; merus stout, about 0.8 of ischiobasis length; carpus short, falling short of midlength of merus, stout; propodus subtriangular, anteromesial margin feebly produced, with sparse setae, ventromesial angle with single long seta; dactylus moderately broad, mesial margin almost straight, with dense stout marginal setae; exopod with well-developed compressed flagellum overreaching propodus, terminally with 4 long setae and single subapical seta; epipod subquadrate to broadly rounded, without podobranch. Third maxilliped (Fig. 5H) with endopod reaching midlength of scaphocerite; coxal plate well developed, oval; antepenultimate segment fused to basis, suture obsolete, combined segment slightly twisted, with long ventral setae, without distolateral spinules; penultimate segment 0.7 times as long as combined preceding segment, ventral surface with long setae; ultimate segment 0.6 of penultimate segment, tapering distally, with transverse ventromedial and dorsal rows of long setae; exopod reaching 0.7 of antepenultimate segment length, well-developed, compressed, with 4 long distal plumose setae, and about 7 subdistal short plumose setae; small arthrobranch with about 7 lamellae present. First pereiopod (Fig. 6 A−C) slender, reaching distal margin of scaphocerite by half of palm. Coxa and basis short, both with small distoventral setose tubercle, basis in addition with several proximoventral setae; ischium slender, about 3.5 times longer than distal depth; merus about 1.7 times longer and slightly slenderer than ischium, uniformly deep, unarmed; carpus 0.7 of merus length and 5.5 times longer than wide distally, with longitudinal row of long grooming setae distoventrally (Fig. 6B, C). Chela subequal to carpus length and 0.45 of pocl, palm subcylindrical, slightly compressed, with 3−4 transverse rows of short, serrulate grooming setae proximoventrally; dactylus 1.2 times longer than palm, both fingers terminating in small, hooked unguis, cutting borders situated laterally, unarmed. Second pereiopods (Fig. 6 D−G) well developed, similar, reaching distal margin of scaphocerite by half of carpus, chelae held with dactylus laterally. Coxa and ischium short, stout, unarmed; ischium elongate, slightly widen