Paguropsis confusa, Lemaitre, Rafael, Rahayu, Dwi Listyo & Komai, Tomoyuki, 2018

Lemaitre, Rafael, Rahayu, Dwi Listyo & Komai, Tomoyuki, 2018, A revision of " blanket-hermit crabs " of the genus Paguropsis Henderson, 1888, with the description of a new genus and five new species (Crustacea, Anomura, Diogenidae), ZooKeys 752, pp. 17-97 : 44-51

Paguropsis confusa sp. n. Figs 8D, 11, 12, 13, 14D, 28C, D, Table 1

Type material.

Holotype, male 13.6 mm, Philippines, Bohol Sea, Maribojoc Bay, PANGLAO 2005, NODA-BFAR, staCP 2331, 09°39'N, 123°48'E, 256-268 m, 22 May 2005 (MNHN 50015).

Paratypes.

Philippines: MUSORSTOM 1, NOVauban: N of Lubang, staCC 12, 14°00'N, 120°17'E, 187-210 m, 20 Mar 1976: 5 males 9.7-11.2 mm, 3 females 7.9-9.7 mm, 2 ovig females 9.2, 10.4 mm (MNHN-IU-2014-9397). MUSORSTOM 3, NOCoriolis: W of Luçon, staCP 90, 14°00'N, 120°19'E, 195 m, 31 May 1985: 9 males 6.9-10.3 mm, 1 female 9.7 mm (USNM 1441901); N Cebu Island, staCP 143, 11°29'N, 124°11'E, 205-214 m, 7 Jun 1985: 1 male 20.9 mm (MNHN-IU-2014-9396); NE of Cebu Island, staCP 145, 11°01'N, 124°04'E, 214-246 m, 7 Jun 1985: 4 males 9.8-13.5 mm, 2 ovig females 11.0, 11.7 mm (MNHN-IU-2014-9398). LUMIWAN 2008, NODA-BFAR: N of Lubang, staCP 2867, 14°02'N, 120°12'E, 189-93 m, 23 Mar 2008: sex indet, not examined, color photograph (Fig. 28D) (MNHN).

South China Sea: INVMAR, [off Vietnam], sta 69, Cr. 4/63, 15°55'44"N, 15°57'54"N, 109°8'30"E -109°36'30"E, 260-315 m, 16 Sep 1963: 3 males 7.6-11.8 mm ( MNHN-IU–2014– 9419, = MNHN Pg 2314). Hong Kong: Cr. 4163, sta 66, Tr. 56, coll. Hong Kong Fisheries Research Station, [no other data]: 1 female 6.4 mm (MNHN-IU-2013-5658).

Indonesia: CORINDON 2, NOCoriolis: Kalimantan, Makassar Straits, sta CH 208, 00°15'S, 117°52'E, 150 m, 31 Oct 1980: 1 male 10.3 mm (MNHN-IU-2014-9377).

Western Indian Ocean: MIRIKY: Madagascar, between Nosy-bé and Banc du Leven, staCP 3188, 12°31'S, 48°22'E, 298-301 m, 27 Jun 2009, colls. P Bouchet, N Puillandre & B Richer de Forges: 2 specimens not examined, identified and sexed from color photographs, 1 female (#50), 1 ovig female (#51) (MNHN). MAINBAZA, NOVizconde de Eza: Mozambique Channel, Maputo transect, staCP 3134, 25°11'S, 35°14'E, 303-403 m, 10 Apr 2009, colls. P Bouchet, J Rosado & E Strong: sex indet. (specimen #23), not examined, color photograph (Fig. 8D) (MNHN). DST/NRF ACEP: off Durban, KwaZulu-Natal, South Africa, RY Angra Pequena, sta R45 Echinoderm Extravaganza, 29°52.80'S, 31°11.76'E, 215 m, 23 Jun 2016, ROV: specimen not collected, color photograph in situ (Fig. 28C).

[Locality uncertain]: INVMAR: sta 8, 5 Dec 1963 [no other data]: 1 male 10.3 mm (MNHN-IU-2014-9424, = MNHN-Pg 2312); sta 26, [no other data]: 4 males 5.5-11.8 mm, 1 female 7.1 mm (MNHN-IU-2014-9421, = MNHN Pg 2319); sta 28, [no other data]: 3 ovig females 8.1-11.3 mm (MNHN-IU-2014-9420, = MNHN Pg 2318); sta 64, 16 Sep 1963: 3 males 6.2-9.7 mm, 2 females 5.2, 7.3 mm (MNHN-IU-2014-9417, = MNHN Pg 2317).

Description.

Shield (Figs 8D, 11A, 12A) subtriangular, ca. 1.3 times as long as broad; dorsal surface glabrous except for anterolateral setae and transverse fringe of short setae on sloping anterior margins of gastric region; anterior margin between rostrum and lateral projections concave; lateral projections broadly triangular, each terminating in small spine; posterior margin roundly truncate; lateroventral distal angle produced into strong blunt spine adjacent to proximal margin of first antennal segment. Rostrum (Figs 8D, 11A, 12A) acutely subtriangular, arched dorsally, strongly produced and extending to distal margin of ocular acicles; with distinct rounded dorsal longitudinal ridge having few short setae laterally, and 1 minute subterminal spine. Branchiostegite with 1 spine on dorsodistal angle of anterodorsal plate, and setose distal margin.

Ocular peduncles ca. 0.4 length of shield, constricted medially and broadening distally, glabrous except for dorsal longitudinal row of short setae; corneas strongly dilated, diameter 0.5-0.6 total peduncular length (including the cornea). Ocular acicles small, triangular, each armed with distal spine directed anteriorly.

Antennular peduncles when fully extended overreaching distal margins of corneas by full length of ultimate peduncular segment; ultimate and penultimate segments glabrous or at most with scattered short setae; basal segment with ventromesial tuft of setae distally; lateral face with distal subrectangular lobe, small medial spine, and setose lobe proximally.

Antennal peduncles overreaching distal corneal margins by ca. 0.3 length of ultimate segments. Fifth and fourth segments unarmed, nearly glabrous except for scattered short setae. Third segment with setose spine at ventrodistal angle. Second segment with dorsolateral distal angle produced, terminating in small simple or bifid spine; mesial margin rounded, setose, dorsomesial distal angle with small spine. First segment unarmed except for setae on lateral face. Antennal acicle relatively short, reaching at most to distal margin of optic calathus, slender, nearly straight and terminating in sharp spine, with few long setae distally. Antennal flagellum long, reaching to distal end of cheliped fingers, with few, scattered short setae less than 1 flagellar article in length.

Mouthparts not markedly different from those described for Paguropsis typica (see Fig. 4 A–F). Maxilliped 3 with exopod ca. 4.1 times as long as broad.

Chelipeds (Figs 8D, 11B) subequal, similar in armature and setation; dorsal surfaces of chelae and carpi covered with moderately dense tufts or short rows of long, bristle-like setae not hiding ornamentation beneath; ventral surfaces of palms smooth except for 2 submedian longitudinal rows of well-spaced low tubercles each with tuft of long bristle-like setae. Dactyl and fixed finger with narrow hiatus proximally when closed, forming spoon-like shape in ventral view when closed; each terminating in small curved corneous claw and subdistal blunt calcareous tooth ventral to claw, both claws and teeth interlocking when fingers closed; cutting edge of dactyl with terminal row of small, fused corneous teeth on distal one-third, and row of unequal calcareous teeth on proximal two-thirds; cutting edge of fixed finger with row of blunt calcareous teeth decreasing in size distally. Dactyl ca. 1.2 times as long as palm; dorsal surface convex, with numerous tufts of long bristle-like setae, and few small blunt spines proximally; dorsomesial margin rounded, usually with patch of short dense plumose setae medially; ventral face with well-spaced tufts of long bristle-like setae inserted at bases of small tubercles, lacking spines. Fixed finger with dorsal, lateral, and ventral surfaces similar to dactyl in armature. Palm as long as carpus, dorsal surface covered with numerous small spines arranged in more or less irregular longitudinal rows of spines with tufts of long setae; dorsomesial margin with row of 6-8 spines with tufts of long setae; dorsolateral margin rounded, not delimited, with irregular rows of small tubercles or spines, each accompanied by long setae. Carpus 0.5-0.6 times length of merus; dorsal and dorsolateral surfaces with well-spaced spines or short transverse rows of 2 or 3 small spines each bearing tufts of long setae; dorsolateral margin rounded; dorsomesial margin with row of strong spines each bearing tufts of long setae; mesial surface with short transverse rows of bristle-like setae, otherwise smooth; ventral surface smooth except for fringe of long setae on ventrodistal margin extending on to mesial surface. Merus nearly as long as chela, subtriangular in cross-section; dorsal margin with row of low protuberances each bearing transverse row of 2 or 3 small tubercles and bearing tuft of long setae; ventromesial and ventrolateral margins each with irregular row of spines with tufts of long setae; lateral and mesial surfaces with tufts of long and short setae. Ischium with row of small spines on ventrolateral margin. Basis with ventromesial row of long setae. Coxa with well-marked longitudinal fissure (Fig. 11C) on ventral surface.

Pereopods 2 and 3 (Figs 8D, 13 A–D) similar in armature and setation, distinctly dissimilar in length, with pereopod 2 distinctly shorter than pereopod 3. Dactyls ca. 1.4 (pereopod 2) or 2.3 (pereopod 3) times as long as propodi, broadly curved, each terminating in sharp corneous claw; dorsolateral and dorsomesial margins with short oblique rows of bristle-like setae; dactyl of pereopod 3 becoming slender distally, ca. 1.4 times as long as dactyl of pereopod 2; lateral surface with proximal third having shallow or weakly distinct longitudinal concavity; ventromesial margin armed with 10-15 minute corneous spinules (pereopod 2) or unarmed (pereopod 3), and with tufts of long bristle-like setae. Propodi ca. 1.4 (pereopod 2) or 1.1 (pereopod 3) times as long as carpi; dorsal surfaces with short tufts of setae, ventral surfaces with tufts of long setae. Carpi unarmed except for tufts of setae dorsally and distolateral fringe of long setae. Meri with fringe of long setae on ventral margins; ventral margin of merus of pereopod 2 with or without row of small blunt spines (frequently lacking or fewer spines in specimens SL ≤ 11.0 mm) hidden by setae. Ischia armed with row of few small spines and long setae (pereopod 2) or unarmed and scattered setae (pereopod 3). Coxae with ventromesial margin sparsely setose; coxae of pereopods 3 (Fig. 11C) narrowly separated by 0.2 ventral length of 1 coxa. Sternite XI (Fig. 11C) having anterior lobe flat or weakly concave medially, glabrous; posterior lobes compressed, each with transverse fringe of setae.

Pereopod 4 (Figs 12B, 14D) with chela as long as carpus and 3.2-3.6 times as long as high, palm 1.8-2.0 times as long as high. Dactyl and fixed finger leaving wide gap when closed, each terminating in sharp, inwardly curved corneous claw crossing when closed. Dactyl strongly curved inward, dorsal margin with row of short setae; cutting edge with ventrolateral distal row of up to 8 small corneous-tipped spines (in addition to corneous claw). Fixed finger curving inward, cutting edge with 3 or 4 strong corneous-tipped spines (in addition to corneous claw) arranged like bear claw; lateral face usually with 1-4 minute scale-like corneous spines near base of finger. Palm straight, ca. 2.1 as long as high; dorsal margin with 2 interspersed fringes of setae, 1 of short thick setae and 1 of long thin setae; ventral margin with tufts of setae continued sparsely on fixed finger. Carpus unarmed except for fringe of long setae on dorsal margin, and fringe of short thick setae on dorsodistal angle of lateral face; with scattered short setae ventrally. Merus 0.5-0.6 times as long as meri of pereopod 2 and pereopod 3, respectively. Sternite XII (Fig. 11C) weakly divided medially, each side with fringe of long dense setae.

Pereopod 5 (Fig. 12C) with chela ca. 0.6 times as long as merus, with long, brush-like setae on dorsal and ventral surfaces; merus and carpus each with dorsal and ventral row of long setae. Dactyl with propodal rasp on ventral face. Propodal rasp consisting of minute, ovate scales, occupying 0.2 length of propodus. Ischium with setae dorsally and ventrally. Coxa with fringe of long bristle-like setae on rounded ventromesial distal angle.

Male gonopod 1 with inferior lamella armed on distal margin with posterior row of slender, semitransparent hook-like spines, and 2-4 anterior irregular rows of small, straight or slightly curved corneous spines. Gonopod 2 with distal segment strongly twisted distally, densely setose; usually with unpaired, reduced pleopods 3-5 on left side or less frequently on right side, as follows: biramous pleopods 3 and 4, and uniramous, vestigial pleopod 5 (see “Variations”).

Female with unpaired pleopods 2-5 on left side or less frequently on right side, as follows: pleopods 2-4 biramous, well developed, and reduced biramous or uniramous and vestigial pleopod 5 (see “Variations”). Brood pouch large, subquadrate, distal margin scalloped and fringed with setae.

Uropodal exopods (Fig. 12D) slender, broadly curved, terminating in strong spine, anterior margin with fringe of long setae and row of well-spaced corneous-tipped spines; endopods short, strongly curved, anterior margin with long setae and 1 or 2 irregular rows of corneous-tipped spines; protopods with strong, ventrally curved proximal spine.

Telson (Fig. 12D) subrectangular, wider than long; posterior lobes separated by weak shallow median cleft, terminal margins unarmed except for fringe of long setae.

Genetic data.

See Table 1.

Color

(Figs 8D, 28C, D). Shield light orange except for pink medial area just posterior to rostrum. Ocular peduncles light orange except for white proximal margins and white distal margins bordering black corneas; ocular acicles mostly light orange except for white distal margins and white distal spine. Antennules light orange, flagella of similar but darker color than peduncle. Antennal peduncles light orange, and similar but lighter toned and somewhat transparent flagella. Chelipeds with white spines and tubercles; chelae white except for light orange proximally on dorsal surface of palms and near bases of dactyls and fixed fingers; carpi orange; meri with reddish dorsal margins, and two short dark red stripes on distolateral and distomesial margins. Pereopods 2 and 3 with white except as follows: dactyls each with orange stripe on lateral face interrupted at proximal one-fifth; propodi each with two broad orange bands (fading dorsally and ventrally), one band on lateral face proximally and another distally; carpi each with orange portion dorsodistally, ventrally, and proximally; meri each with light orange dorsal and ventral margins, and short orange band laterodistally; ischium with light orange dorsal margin.

Etymology.

The specific name is derived from the Latin feminine singular of confuso, meaning confusion or disorder, and in reference to the state of morphological confusion that had prevented the unmasking of this and other new species under the name P. typica .

Distribution.

Western Pacific: from Philippines, South China Sea, and Indonesia (Kalimantan) on the Macassar Strait. Western Indian Ocean: Mozambique Channel to off Durban, South Africa. Depth: 150 to 403 m.

Habitat and symbiont.

Found with indeterminate species of acontiate anemone (see “Remarks” under genus).

Variations.

Among the 31 males and 16 females examined, 99% of males had pleopods 3-5 on the left side, and 37.5% of females had pleopods 2-5 on the left side. There is no other appreciable morphological variation other than that incorporated in the description.

Affinities.

This new species is superficially similar to P. andersoni , from which it differs drastically in coloration and several other characters. Generally, P. confusa sp. n. has a delicate morphology, in particular the less strongly armed chelipeds and slenderer pereopods 2 and 3 than in P. andersoni (see Figs 10 A–D, 13 A–D). The proximal one-third of the lateroproximal surface of the dactyl of pereopod 3 is weakly or indistinctly concave, whereas the lateroproximal surface is has a distinctly marked concavity in P. andersoni . The coxae of pereopods 3 are narrowly separated from each other in both species (by 0.2 ventral length of 1 coxa), but the posterior lobes of sternite XI (Figs 5D, 11C) are noticeably less compressed in P. confusa sp. n. than in P. andersoni . The discovery of the drastically different coloration patterns of these two species made possible, in part, the morphological separation of the two (compare Figs 8C, D, 28C, D).