Ancylomenes speciosus
Creators: name: Ďuriš, Zdeněk
name: Fišarová, Karolína
name: Šobáňová, Anna
name: Lin, Chia-Wei
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Palaemonidae
Ancylomenes
Ancylomenes speciosus

description: 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 widened distally, almost 5 times longer than distal depth; merus uniformly slender, entire, as deep as and 1.25 times as long as ischium; carpus 0.75 times as long as merus and 0.5 of pocl, stout, slightly widening distally, unarmed. Chela slightly bowed, 1.1 times as long as carapace, 2.2 times as long as carpus; palm about 3 times longer than deep distally, slightly compressed; dactylus about 0.7 of palm length, terminating in acute hooked unguis, cutting border situated laterally, basal half armed with 3 or 4 acute recurved, proximally diminishing teeth, remaining part entire, sharply edged; fixed finger generally similar to dactylus, armed on basal half with 3 or 5 acute, recurved, proximally diminishing teeth.
Ambulatory pereiopods (Fig. 7) long and slender. Third pereiopod (Fig. 7A, B) slightly overreaching distal margin of scaphocerite. Coxa and basis short, unarmed, ischium elongate, about twice longer than basis, merus straight, slender, uniformly deep, about 10 times longer than deep and 2.4 times longer than ischium, unarmed; carpus unarmed, half of merus length, distodorsal lobe prominent; propodus about 0.95 times of merus length and twice as long as carpus, slender, 18 times longer than deep, armed with 2 long distoventral spines subequal to distal propodus depth, and 3 spaced single spines on distal half of ventral margin, with scattered long setae dorsally and ventrally on distal half of propodus; dactylus about 0.2 of propodus length, slender, 4 times longer than basal depth, compressed, dorsal margin broadly convex, weakly bowed basally, terminating with long slender acute unguis about 0.6 times as long as corpus, ventral margin with single accessory distal tooth reaching about 0.6 of unguis length.
Fourth pereiopod (Fig. 7C, D) slightly slenderer, otherwise similar and subequal to third pereiopod.
Fifth pereiopod (Fig. 7E, F) longer than preceding two legs, overreaching distal margin of scaphocerite by length of dactylus; both carpus and propodus 1.2 times as long as respective segments of third pereiopod; propodus with ventral margin with tufts of distoventral setae, single distoventral spine, with one pair of spines and 1 shorter spine more proximal to subterminal pair.
Uropod (Fig. 4D, F) with protopodite posterolaterally produced; both rami broad, far overreaching posterior margin of telson; exopod posterior margin broadly rounded, lateral margin nearly straight, terminating in small slender acute tooth, with larger slender mobile spine just mesial; diaeresis concave, incomplete; endopod elongately ovoid, falling short of exopod.
Variation. Subadult New Caledonian male, pocl 1.8 mm, MNHN-IU-2018-728 (Fig. 8), with body damaged, covers soft, post-moulted. Rostrum (Fig. 8A) falling short to reach distal margin of intermediate segment of antennular peduncle, rostral formula 1 + 7/2, dorsal outline of carapace with slight tubercle posterior to epigastric tooth; infraorbital angle produced, subacute, carapace otherwise as in New Caledonian female; upper flagellum of antennule with 6 segments fused, shorter free ramus with 3 segments; first pereiopod (Fig. 8B) chela distinctly longer than carpus (vs subequal in New Caledonian female); second pereiopod (Fig. 8 C−E) carpus subequal to palm (vs distinctly shorter), fingers subequal to palm (vs distinctly longer), cutting edges of fingers entire, unarmed. Pleon with third somite posterodorsally excavate, compressed, subcarinate, pleurae 1−3 without ventral membranous lobes typical for adult Ancylomenes females. First male pleopod (Fig. 8F) with endopod small, reaching level of proximal ¼ of exopod, generally oval, distomedially obliquely truncated forming angulate apex and obsolete appendix interna arising at distal ¼ of medial margin, with two dorsolateral pappose setae and single proximomedial pappose seta. Endopod of male second pleopod (Fig. 8G) with appendices interna and masculina arising at proximal third of medial margin; appendix interna slender, 0.3 of endopod length, slightly overreaching tip of appendix masculina, with few distal cincinnuli; appendix masculina with two terminal serrate setae, otherwise unsetose. Sixth pleomere dorsal length 2.8 times greater than maximum depth, and 1.4 times greater than pocl.
Juvenile Australian female specimen, pocl 1.5 mm, MTQ W.33108 (Fig. 9), soft-shelled, damaged: rostral formula 1 + 7/1, dorsal outline of carapace with slight tubercle posterior to epigastric tooth; infraorbital angle obtusely produced, not acute, carapace otherwise as in New Caledonian female, pleon without ventral membranous lobes on pleurae 1−3, sixth pleomere dorsal length 3.2 times greater than maximum depth, and 2.1 times greater than pocl; first and second cheliped distal segments dimensions as in New Caledonian male (above), cutting edges unarmed.
Subadult Taiwanese male, pocl 2.7 mm, NMMBCD5629: morphologically generally as New Caledonian female, differs in some characters; rostral formula 1 + 6/3, ventral teeth minute, most posterior ventral tooth positioned more posteriorly than in compared female, on about distal 0.4 of rostrum length; sixth pleomere dorsal length 2.8 times greater than maximum depth, and 1.4 times greater than pocl (while almost subequal in adult females); first and second cheliped distal segments proportions as in both New Caledonian male and Australian subadult female (above), cutting edges dentition (dactylus/fixed finger) 1/2. Adult Taiwanese male, pocl 3.5 mm, NMMBCD5630: with second pereiopod carpus shorter than palm, fingers dentition 2/3. Three adult Taiwanese females, pocl 4.1−4.5 mm, NMBBCD5631, 5632, 5634: well-developed membranous rounded lobe protruding ventrally on each of first three pleurae, second pereiopod carpus distinctly shorter than palm, fingers dentition 3/4, 3/4, and 1/3, respectively. Rostrum dentition in Taiwanese specimens ranging 1−2 + 6−8/1−2.
Ovigerous female paratype, Japan, pocl 5.5 mm, RMNH D.50660: with well-developed ventral membranous lobes on pleurae 1−3; rostrum dentition 2 + 7/3.
Coloration. New Caledonian ovigerous female MNHN-IU-2018-1358 (Figs. 1, 2, 12A). Body and appendages generally transparent. Carapace with rostrum transparent, 0.4−0.8 of dorsum with posteriorly directed anchorlike bright white figure with subacute crown apex, lateral arms wide, truncate, shank short, widely expanding to sides anteriorly; mediodorsal line with 4 reddish spots situated ahead of anchor figure, anteriorly and posteriorly on shank, and posteriorly on crown apex; lateral regions with scattered purplish red and two white spots. Third pleomere with large cordiform bright white patch (slightly translucent in middle) over posterior half of dorsum, with broadly rounded three anterior lobes and wider rounded posterior lobe, all lobes outlined by red; sides of pleon within pleurae 1−4 with 5 bright white patches, second to fourth patches large, circular, all irregularly interspaced by smaller red spots; rounded ventral expansions of females pleura 1–3 with short vertical red and white band; bottom of transparent pleomeres 1–5 with white median patches and red transverse bands, with reddish tinge over eggs. Eyestalk with red stripe ventrally and white line anteriorly (when eyes extended to sides), and with white line posteriorly continuing across ophthalmic somite, cornea greyish white, with horizontal pale reddish band and dorsal spot. Antennae and scaphocerite transparent, except whitish statocysts, mouth region (Fig. 2B) with scattered reddish spots. Chelae, carpi and meri of both pairs of chelipeds largely bright white, with articulation regions and tips of fingers dark purple to purple-red; first pereiopod fingers purple with whitish apices, those of second pereiopods white anteriorly on proximal half, purple distally, with orange apices. Pereiopods 3−5 generally transparent, with only coxae of pereiopods 4 reddish. Tail fan with red transverse band anteriorly, posterior 0.6 of both telson and uropodal endopods white, with yellowish tinge distally on endopods; exopod with distal 0.7 of length white, with large bright purple eyespot with bluish centre on distal half.
New Caledonian subadult male MNHN-IU-2018-728. Damaged post-moulted specimens, post mortem examined, showing, in reduced extent, similar pattern as New Caledonian female, mainly typical red and white cordiform spot dorsally on third pleomere, purple-white pattern on chelipeds and tail fan, and reddish-purple colouration of eyestalks and bases of fourth ambulatory legs; in addition, remains of reddish colour present on bases of pleopods.
Australian female, MTQ W.33108 (Figs. 10A, 12B). Colouration very similar to that of New Caledonian female, with typical pattern on chelipeds, third pleomere dorsal spot, and tail fan, with just cordiform dorsal spot on pleon with white background roughly diffused, latter with U-shaped field of reduced colour in middle separating anterior median white lobe from both lateral ones, all lobes with red anterior spot; second chelipeds as in New Caledonian specimens, but carpi with bright white colour concentrated into pair of longitudinal lines; eyes also coloured as described above, but with interocular line separating basally in eyestalks from posterior white lines there. Red spots basally on pleopods well marked, as in New Caledonian male.
Taiwanese subadult male NMMBCD5629 (Fig. 10B): colour pattern as in New Caledonian male. Two adult Taiwanese specimens photographed, i.e. male NMMBCD5630 (Figs. 11A, 12D), and ovigerous female NMMBCD 5631 (Figs. 11B, 12E), with dorsal pleonal spot as described by Okuno (2004: 872) for his holotype male: …“ third somite with large dorsal round patch over posterior two thirds, narrower posteriorly than anteriorly, background white, with many red spots on anterior half (the white background being reduced to a network of pale orange irregular lines between the spots), posterior margin pinkish ”… (see Okuno, 2004: Fig. 5, and present Fig. 12C). Further, he also noted there, that …“ Pleura of first to fourth abdominal somites without spots in male, with purplish red and white oval patches at first to fourth pleura in female ”…. Taiwanese male NMMBCD5630 (Fig. 12D) possessing those red and white oval patches submarginally on pleurae, similarly as ovigerous female NMMBCD5631, with those spots reaching spots on membranous ventral lobes (Figs. 11B, 12E); latter female also with series of four oval white spots more dorsally on three anterior pleurae, interspaced by short red vertical spots (similar to New Caledonian female; Fig. 2).
Measurements [mm]. See Table 2.
Hosts, habitat and ecology.
Observed in association with actiniarians of the genera Entacmaea Ehrenberg, Antheopsis Simon, Megalactis Hemprich & Ehrenberg, and Stichodactyla Brandt, and with the caryophyllid scleractinian genus Euphyllia Dana (see Okuno, 2004: Table 1). The sea anemone Antheopsis maculata (Klunzinger, 1877) was reported as host by Saito (2015). Coleman (2002) also recorded A. speciosus (as Periclimenes) from the soft coral genera Sarcophyton Lesson and Dendronephthya Kükenthal.
No data are available on the host of the New Caledonian and Taiwanese specimens herein examined; only the single New Caledonian male specimen was reported as captured from an “ unidentified carpet sea anemone ” [Stichodactyla?] on sandy bottom. The Australian specimen was obtained from the sea anemone Heteractis sp. situated near the base of a reef wall at a depth of 16.2 m. This specimen, a juvenile female, was observed and videorecorded moving among the anemone tentacles, occasionally feeding on the host’s mucus with detritus particles. During that time, it ceaselessly exhibited the side-to-side body swaying, most frequently shown by fish cleaning palaemonid shrimps (Horká et al., 2018), already reported for the species by Okuno (2004) and Okuno and Bruce (2010). The present material was obtained in depths between 12.6 and 26– 29 m.
Distribution. Japan: type locality—Boso Peninsula, Honshu, depth 18 m; also known from Izu Islands, Ogasawara Islands, East China Sea coast of Kyushu, Ryukyu Islands (Okuno, 2004), and Izu-Ohshima Island, depth 20 m, associated with the sea anemone Antheopsis maculata (Klunzinger, 1877) (Saito, 2015); Taiwan: SW coast, Pingtung County, 26–29 m (present report); Australia, Great Barrier Reef, Lizard Island (present report); and New Caledonia: NW coasts, Koumac (present report). Nevertheless, already Okuno (2004: 874) stated, that: “ The species reported as P. holthuisi by Catala (1979), Coleman (1991) and Jones and Morgan (1994), and as P. venustus by Coleman (2002) will be conspecific with P. speciosus without hesitation on account of the characteristic colour in life mentioned above. Steene (1990) recorded Periclimenes sp. taken at the Abrolhos Islands, Western Australia, and this object is same individual to be reported as P. holthuisi by Jones and Morgan (1994). These records suggest, therefore, that P. speciosus is also distributed in Australian and New Caledonian waters ”. Subsequently, Bruce (2010b) mentioned Coleman’s (1988) report of A. holthuisi from Heron Island, Australia as also belonging to A. speciosus. Bruce (2011: 67) also suggested the occurrence of the species from Indonesian waters, based on damaged material from the Banda Sea. Its occurrence in Indonesia was confirmed on the basis of a photo from NE Sulawesi, Celebes Sea (Ryanskiy, 2014: 38), who also mentioned the species from the Philippines and Papua New Guinea, without further data or photos.
description: Published as part of Ďuriš, Zdeněk, Fišarová, Karolína, Šobáňová, Anna & Lin, Chia-Wei, 2024, The West Pacific anemone-shrimp Ancylomenes speciosus (Okuno, 2004) (Crustacea: Decapoda: Palaemonidae) - a species complex or single species?, pp. 269-292 in Zootaxa 5529 (2) on pages 272-286, DOI: 10.11646/zootaxa.5529.2.3, http://zenodo.org/record/14022357