Paragiopagurus acutus
Creators: name: Lemaitre, R.
Publisher: name: Zenodo
Year: 1996
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Parapaguridae
Paragiopagurus
Paragiopagurus acutus

description: <i>Paragiopagurus acutus</i> (DeSaint Laurent, 1972) Figs 25, 26 <i>Parapagurus acutus acutus</i> De Saint Laurent, 1972: 113, figs 7, 18 (type locality: Philippines, <i>Albatross</i> sta. 5222). <i>Sympagurus acutus acutus.- Lemaitre,</i> 1989: 37.- Lemaitre, 1994: 412. Holotype. Male (SL 5.6 mm), Philippines, 9.2 mi (17 km) NW of W San Andreas Is., between Marinduque and Luzon, <i>Albatross</i> sta. 5222, 13°38'30"N, 121°42'45"E, 357 m, 24 Apr 1908, USNM 168309. Australian Material. WESTERN AUSTRALIA: 1 male (SL 4.6 mm), NW of Leveque, FRV <i>Soela,</i> sta. <i>01184/065,</i> 14°49.0'S; 121°36.1'E, 302 - 300 m, 12 Feb 1984, colI. S. Slack-Smith, WAM 1239 -86. Other material. (For meaning of asterisks see Materials and Methods). JAPAN: 1 male (SL 6.1 mm), Honshu, Uraga Strait, <i>Albatross</i> sta. 5094, 35°04'42"N, 139°38'20"E, 161 m, 26 Oct 1906, USNM 168973 *. PHILIPPINES: 14 males (SL 3.4-6.0 mm), 9 females (SL 2.8-4.8 mm), Verde Is. Passage, off Matocot Point, <i>Albatross</i> sta. 5268, 13°42'N, 120°57'15"E, 311 m, 8 JUll 1908, USNM 168980 *. 7 males (SL 2.1-3.5 mm), between Cebu and Bohol, off Lauis Point, <i>Albatross</i> sta. 5412, 10009'15"N, 123°52'E, 296 m, 23 Mar 1909, USNM 168977 *. 2 males (SL 2.7, 3.2 mm), between Cebu and Bohol, off Lauis Point, <i>Albatross</i> sta. 5411, 1O°1O'30"N, 123°51'15"E, 265 m, 23 Mar 1909, USNM 168976 *. 2 males (SL 4.2, 4.8 mm), Verde Is. Passage, off Matocot Point, <i>Albatross</i> sta. 5297, 13°41'20"N, 120058'E, 362 m, 24 Jul 1908, USNM 168975 *. 1 female (SL 4.1 mm), Verde Is. Passage, off Matocot Point, <i>Albatross</i> sta. 5269, 13°39'50"N, 120059'30"E, 402 m, 8 JUll 1908, USNM 168974 *. INDONESIA: 1 male (SL 5.2 mm), Borneo, Darvel Bay, off Sibutu Is., <i>Albatross</i> sta. 5579, 04°54'15"N, 119°09'52"E, 320 m, 25 Sep 1909, USNM 168978 *. 1 female (SL 6.4 mm), Borneo, Sibuko Bay, off Silungan Is., <i>Albatross</i> sta. 5592, 04°12'44"N, 118°27'44"E, 558 m, 29 Sep 1909, USNM 168979 *. 1 female (SL 5.8 mm), Den danske Kei Ekspd. 1922, sta. 59, 05°28'S, 132°36'E, 385 m, 12 May 1922, ZMK. 4 males (SL 3.3- 7.4 mm), Den danske Kei Ekspd. 1922, sta. 44, 05°39'S, 132°23'E, 268 m, 30 Apr 1922, ZMK. 1 male (SL 6.7 mm), Den danske Kei Ekspd. 1922, sta. 51, 05°40'1O"S, 132°21'E, 263 m, 3 May 1922, ZMK. 3 males (SL 2.1- 8.0 mm), 2 females (SL 2.0, 3.3 mm), 4 females ovig. (SL 2.6-6.8 mm), Th. Mortensen's Java-S. Afrika Exp. 1929-30, sta. 7, 08°29'S, 114°40'E, 200 m, 5 Apr 1929, ZMK *. Diagnosis. Phyllobranchiate gills. Shield (Fig. 25a) as long as broad; dorsal surface weakly calcified medially; rostrum broadly rounded, with low dorsal ridge; anterior margins weakly concave; lateral projections subtriangular, terminating in small spine; ventrolateral margin with spine (not always visible in dorsal view); posterior margin broadly rounded. Ocular peduncles more than half length of shield; ocular acicles subtriangular, terminating in strong multifid spine; corneae slightly dilated. Maxillule with internal lobe of endopod bearing 4 long seta. Sternite of 3rd maxillipeds with small spine on each side of midline. Epistomial spine straight. Antennular peduncle exceeding distal margin of corneae by 0.75 length of ultimate segment. Antennal peduncle (Fig. 25b) reaching distal margin of cornea; 2nd segment with dorsolateral distal angle produced, terminating in strong simple spine reaching to midpoint of antennal acicle; acicles reaching distal margin of corneae, mesial margin with 9 to 14 spines; flagellum with short and long setae &lt;1 to 4 flagellar articles in length respectively. Che1ipeds markedly dissimilar, with moderately dense setae. Right cheliped (Fig. 25d,e) with palm broader than long or about as broad as long in large specimens (SL ca 6.0 mm); fingers curved ventromesially, dactyl with strongly concave and smooth ventromesial face; dorsal face of palm with scattered small spines or tubercles, ventral face smooth or with small tubercles; palm with dorsolateral and dorsomesial margins each well delimited by row of spines, ventromesial margin rounded, occasionally with row of 2 or 3 blunt spines proximally; carpus with numerous small spines or tubercles on dorsal surface, and well delimited dorsolateral margin with row of spines. Left cheliped (Fig. 25c) usually weakly calcified on lateral face of carpus; carpus with dorsal row of 4 to 6 small, well-spaced spines, and strong dorsodistal spine. Ambulatory legs (Fig. 25f,g) with dacty1s having ventromesial row of 7 (3rd pereopod) to 15 (2nd pereopod) small, often minute corneous spines, and dorsal and dorsomesial rows of long setae; carpi each with dorsodistal spine; carpus of 2nd pereopod with dorsal row of 7 small spines. Anterior lobe of sternite of 3rd pereopods setose, armed with 1 spine. Fourth pereopod (Fig. 25h) with propodal rasp consisting of 1 row of ovate scales. Vropods and te1son (Figs 25j, 26) markedly asymmetrical; telson lacking transverse suture separating anterior and posterior lobes; posterior lobes separated by shallow V-shaped median cleft, terminal margins armed with often long, curved corneous spines; in large females (SL&gt; 6.0 mm) posterior lobes armed with several rows of corneous spines on distal margin, rows of spines often extending to dorsodistal surface (Fig. 26a). Males lacking 1st gonopods, with unpaired, uniramous 2nd left pleopod (Fig. 25i). Females with vestigial right 2nd pleopod. Habitat and symbiotic associations. Found in gastropod shells. Distribution. Western pacific: Philippines, China Sea, Indonesia, Japan, and now Australia. Depth: 161 to 558 m. Affinities. <i>Paragiopagurus acutus</i> is most similar to <i>P bicarinatus</i> and <i>P hirsutus.</i> The former can be separated from <i>P bicarinatus</i> by the shape and armature of the mesial face of the right palm. The mesial face of <i>P acutus</i> is not expanded distally, and the ventromesial margin is rounded; the mesial face of <i>P bicarinatus</i> is expanded distally, and the ventromesial margin is well delimited by a row of spines. <i>Paragiopagurus acutus</i> differs from <i>P hirsutus</i> by the armature and setation of the right chela (see Affinities under <i>P hirsutus).</i> Additionally, <i>P acutus</i> reaches a much larger size than <i>P bicarinatus</i> or <i>P hirsutus,</i> and exhibits a stronger degree of sexual dimorphism in the te1son (Fig. 26). Remarks. De Saint Laurent (1972) provisionally proposed three subspecies, <i>Parapagurus acutus acutus, P a. bicarinatus,</i> and <i>P a. hirsutus,</i> for specimens that apparently could be differentiated only by the characteristics of the right cheliped. De Saint Laurent did observe that when all specimens of her subspecies were considered, a great range of variability occurred in the relative length of the ocular peduncles, ocular acicles, and the right cheliped. She proposed a subspecific division for the specimens rather than a specific one because of the impossibility she encountered in assigning specimens that were missing the right cheliped. Subsequently, Lemaitre (1989) transferred the subspecies of <i>P acutus</i> to <i>Sympagurus</i> (sensu Lemaitre, 1989). The study of numerous specimens deposited in various museums previously assigned to De Saint Laurent's (1972) three subspecies, and comparisons with recently collected Australian specimens, clearly show that they are sufficiently distinct morphologically to warrant elevation to specific status. Furthermore, their relatively broad sympatric distributions provides additional support for considering them as full species. The three species are quite similar in a number of characters such as the shape of the ocular acicles, left cheliped, telson, and absence of 1st pair of gonopods in males. However, as previously mentioned, they clearly differ by the shape and armature of the right cheliped.
description: Published as part of <i>Lemaitre, R., 1996, Hermit crabs of the family Parapaguridae (Crustacea: Decapoda: Anomura) from Australia: species of Strobopagurus Lemaitre, 1989, Sympagurus Smith, 1883 and two new genera., pp. 163-221 in Records of the Australian Museum 48 (2)</i> on pages 211-214, DOI: 10.3853/j.0067-1975.48.1996.286, http://zenodo.org/record/4654966
description: {"references": ["Saint Laurent, M. de, 1972. Sur la famille des Parapaguridae Smith, 1882. Description de Typhlopagurus foresti gen. nov., et de quinze especes ou sous-especes nouvelles de Parapagurus Smith (Crustacea, Decapoda). Bijdragen tot de Dierkunde 42 (2): 97 - 123.", "Lemaitre, R., 1989. Revision of the genus Parapagurus (Anomura: Paguroidea: Parapaguridae), including redescriptions of the western Atlantic species. Zoologische Verhandelingen 253: 1 - 106.", "Lemaitre, R., 1994. Crustacea Decapoda: Deep-water hermit crabs (Parapaguridae) from French Polynesia with descriptions of four new species. In: A Crosnier (ed.), Resultats des Campagnes MUSORSTOM, 12. Memoires du Museum national d'Histoire naturelle, Paris, 161: 375 - 419."]}