Sympagurus dimorphus ( Studer, 1883 )

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., Records of the Australian Museum 48 (2), pp. 163-221 : 176-179

Sympagurus dimorphus ( Studer, 1883)

Fig. 7

Eupagurus dimorphus Studer, 1883: 24 , figs 11, 12 (type locality: off Cape of Good Hope, South Africa, S.M.S. Gazelle, 34°13.6'S, 15°00.7'W, 211 m).

Parapagurus dimorphus .-De Saint Laurent, 1972: 108.

Sympagurus dimorphus .- Lemaitre, 1989: 71, figs 36-38, 40E-H.- Lemaitre, 1990: 229.- Lemaitre, 1994: 412.­ Lemaitre & McLaughlin, 1992: 747, figs 1-5, tables 1, 2.

Type material. Syntypes, Museum fUr Naturkunde der Humboldt-Universitiit zu Berlin (not examined).

Australian material. NEW SOUTH WALES: 1 female (SL 5.3 mm), off Newcastle, FRV Kapala , 549 m, Apr 1971, AM P18027. 2 males (SL 4.2, 5.4 mm), E of Broken Bay, FRV Kapala , sta. K80-07-02, 329 m, 5 Oct 1976, AM P40387. 2 males (SL 4.6, 5.5 mm), E of Seal Rocks, FRV Kapala , sta. K78-14-09, 32°23'S, 152°59'E, 503 m, 20 Jul 1978, AM P40402. 1 male (SL 3.2 mm), Ulladulla-Bateman's Bay area , FRV Kapala , sta. K77-03-07/08, 35°32'S, 15°47'E, 549 m, 28 Apr 1977 , AM P40398. 1 female (SL 3.7 mm), SE of Gabo Is. , FRV Kapala , sta. K75-03-02, 37°45-38'S, 150012 -16'E, 402 -439 m, 10 Jul 1975 , AM P20820 .

VICTORIA: 1 male (SL 6.9 mm) , 40 mi (74 km) S of Cape Everard , 400 m, Oct 1914, AM E.6153. 2 males (SL 5.2, 7.5 mm) , off Gabo Is. , 365 m, 11 Nov 1913, AM E. 477l. 1 female (SL 5.5 mm) , eastern slope, Bass Strait , 128-146 m, 29 Nov 1913, AM E.4827. 2 females (SL 4.6, 4.7 mm) , off SE Victoria, 38°14.9'S, 149°26.1'E, CSIRO cruise FR5/ 86, SLOPE 34, 800 m, 23 Jul 1986, NMV Jl 6208. 2 males (SL 5.2, 6.6 mm) , 6 females ovig. (SL 5.2- 6.3 mm), S of Point Hicks, Eastern Bass Strait , HMS Kimbla , sta. K7/73- 8, 38°16'S, 149°26'E, 512 m, 21 Nov 1973, NMV Jl 2126, Jl 6190. 1 male (SL 5.8 mm) , sta. MFG 15, Bass Strait, off Portland , 38°5O'S, 141°46'E, 600 m, 6 Mar 1980, colI. M. Gomon et al., NMV J40405 . 3 males (SL 4.2 -4.6 mm) , 3 females (SL 3.7 -4.4 mm) , off eastern Victoria, CSIRO cruise FB5/86, SLOPE 46 , 42°00.2'S, 148°37.7'E, 720 m, 27 Jul 1986, NMV Jl 619l.

TASMANIA: 3 males ( SL 4.2 -7.0 mm), 2 females ( SL 4.4, 5.3 mm), 1 female ovig. ( SL 5.3 mm), off Babel Is., 124 m, 28 Oct 1912, AM E;3148, P.3545. 2 males ( SL 3.9, 7.2 mm), FRV Soela, S05/84/51, 41°15'S, 144°03'E, 520 - 480 m, 20 Oct 1984, colI. R. Wilson, NMV Jl1396 . 1 female ( SL 5.3 mm), FRV Soela, S 05/84, 41°15'S, 144°08'E, 520 m, 20 Oct 1984, NMV Jl 620l. 3 males ( SL 6.0 - 8.2 mm), 1 female ( SL 6.7 mm), 39 km NE of Cape Tourville , Tasmania Marine Station no. SLOPE 84, 41°53.54'S, 148°39.07'E, 732 m, 30 Oct 1988, colI. G.C.B. Poore et al., NMV Jl6188 , J40406 . 3 males (SL 2.6-4.2 mm), 3 females ovig. (SL 4.1-4.3 mm), Oyster Bay , 110 m, [no date], AM P4484 . 1 female ovig. (SL 5.3 mm), FRV Soela, S 04/84/3, 42° 4l. 9'S, 148°25.l'E, 440 m, 15 Aug 1984, NMV Jl6207. 3 males (SL 6.9- 7.5 mm), E of Maria Is., F/ S Endeavour, 91- 182 m, 1915, AM E6420 . 7 males (SL 2.0 - 5.5 mm), 7 females (SL 2.0-4.0 mm), 3 females ovig. (SL 4.3 -4.4 mm), 25 km E of Port Davey, FRV Soela, sta. S05/84/60, 43°25.3'S, 145°39.8'E, 160 m, 21 Oct 1984, colI. R.S. Wilson, NMV Jl2110 . 1 male (SL 3.7 mm), 3 megalopae (SL l.5 -l. 7 mm), S of Hobart, Dmitry Mendeleev, 43°43'S, 147°46'E, 160 m, 20 Feb 1976, colI. J. Paxton, AM P21968. 1 male (SL 5.8 mm), 2 females ovig. (SL 5.0, 6.3 mm), S of Hobart, Dmitry Mendeleev, 43°48.2'S, 147°50'E, 720- 755 m, 20 Feb 1976, colI. J. Paxton, AM P21962. 7 males (SL 4.8 -6.0 mm), 3 females (SL 2.2 -4.0 mm), 1 female ovig. (SL 4.2 mm), 44 unsexed (left in zoanthid carcinoecia), offTasman Head, Bruny Is., 146 -183 m, AM E.5180. 5 males (SL 7.3 7.6 mm), off South Cape, FS Endeavour , 137 m, 1914, AM E5176 . 7 males (SL 7.3-7.8 mm), off South Cape, 137 m, AM E.5177. 1 female ovig. (SL 5.4 mm), off Maatsuyter Is., Jul 1958, NMV Jl 6197 .

Other material. NEW ZEALAND: 1 male (SL 6.8 mm), BS 812, (0.592), W of Hokianga Harbour , RV Tangaroa, NZOI sta. 0.556, 35°37.6'S, 172°36.5'E, 657 m, 11 Jan 1981, NMNZ Cr 8466. 1 male (SL 9.7 mm), BS 805, WSW of Cape Maria van Dieman , RV Tangaroa, NZOI sta. 0.549, 37°33.1'S, 177°33.8'E, 776- 836 m, 11 Jan 1981, NMNZ Cr 8464. 2 females ovig. (SL 6.5, 6.6 mm), BS 846, (0.592), SE of Aldermen Is. , RV Tangaroa , 37°04.3'S, 176°26.6'E, 807-872 m, mud, 23 Jan 1981, NMNZ Cr 8460. 3 males (SL 6.9- 7.6 mm), 2 females (SL 2.7, 5.3 mm), BS 844, W of White Is. , RV Tangaroa, NZOI sta. 0.590, 37°1O.8'S, 176°38.0'E, 685-705 m, mud, 23 Jan 1981, NMNZ Cr 8467. 1 female (SL 4.3 mm), 1 female ovig. (SL 9.2 mm), BS 761, about 37 km E of Mayor Is. , RV Tangaroa, NZOI sta. R 119 , 37°22.0'S, 176°37.2'E, 616 -666 m, mud, 24 Jan 1979, NMNZ Cr 8475. 1 male (SL 5.0 mm), about 31 km WNW of Orete Point, Cape Runaway , RV Tangaroa, NZOI sta. R 123 , 37°33.1'S, 17T33.8'E, 482 - 353 m, 25 Jan 1979, NMNZ Cr 846l. 1 female (SL 8.5 mm), Bay of Plenty, FV Trinity, 380- 420 m, Nov 1987, NMNZ Cr 8433. 1 juv. sex indet. (SL 2.5 mm), E coast, North Is. , RV James Cook, JlO/60/86, 38°32.4'S, 178°48.4'E, 630 m, NMNZ CR 8426 . 1 male (SL 9.0 mm), Mahia Peninsula, 38°47.5'S, 178°48.7'E, RV James Cook, JlO/52/ 86, 769 m, 31 Aug 1986, colI. WR. Webber , NMNZ Cr 8438. 1 male (SL 12.8 mm), Challenger Plateau, 38°53.6'S, 167°23.7'E, RV James Cook, J2/11181, 841 - 847 m, 24 Jan 1981, NMNZ Cr 844l. 5 males (SL 3.3 -9.3 mm), 1 female (SL 3.9 mm), BS 830, E of Cape Kidnappers , RV Tangaroa, NZOI sta. 0.575, 39°52.8'S, 177°36.5'E, 785 -882 m, mud, 21 Jan 1981, NMNZ Cr 8468. 1 female (SL 4.1 mm), Challenger Plateau, 40006.3'S, 167°57.9'E, RV James Cook, Jl 9/9/84, 919- 922 m, 13 Nov 1984, NMNZ Cr 8454. 1 male (SL 9.2 mm), midway Castlepoint to Cape Tumagain, RV James Cook, J6/3/81, 40049.8'S, 176°50.8'E, 752- 688 m, 12 Apr 1981, colI. G.S. Hardy, NMNZ Cr 8456. 7 males (SL 6.2 -10.5 mm), 1 female (SL 7.8 mm), 3 females ovig. (SL 6.1-8.0 mm), Hikurangi Trench , RV James Cook, J9/04/89, 41° 2l. 6'S, 176°1O.3'E, 710 m, 12 Sep 1989, NMNZ Cr 845l. 3 males (SL 6.8 -9.2 mm), 5 females (SL 6.2 -7.7 mm), 8 females ovig. (SL 5.6 -7.3 mm), NW Westport , RV James Cook, Jl 5115176, 41°25'S, 170043'E, 212 -332 m, 25 Sep 1976, USNM . 7 males (SL 6.9-10.6 mm), 6 females (SL 6.1- 8.1 mm), 1 female ovig. (SL 8.1 mm), BS 672, off Turakirae Head , RV Tangaroa, NZOI sta. R 30 , 41 ° 3l. 4'S, 174°52.6'E, 533 - 225 m, mud and rocks, 15 Jan 1979, NMNZ Cr 8458, 8471, 8483. 10 males (SL 10.4 -14.8 mm), 3 females (SL 7.5- 10.5 mm), BS 643, 41°42.0'S, 175°15'E, RV Tangaroa, NZOI sta. R 1 , Palliser slope, 461 m, mud, 9 Jan 1979, NMNZ Cr 8486, USNM . 1 male (SL 1l. 0 mm), 45 mi (83.2 km) NW of Perpendicular Point ( Westland ), RV James Cook, Jl 5/ 17/76, 41°47'S, 170029'E, 512 -562 m, 26 Sep 1976, NMNZ Cr 8473. 1 male (SL 12.9 mm), 1 female ovig. (SL 10.9 mm), BS 668, about 43 km SE of Cape Campbell , RV Tangaroa, NZOI sta. R 26 , 41°55.9'S, 174°43.2'E, 454- 424 m, 14 Jan 1979, NMNZ Cr 8446. 4 males (SL 9.3- 12.2 mm), 4 females (SL 3.4-6.4 mm), 2 females ovig. (SL 6.3- 7.6 mm), BS 669, about 41 km SE of Cape Campbell , RV Tangaroa, NZOI sta. R 27 , 41°55.8'S, 174°40.7'E, 434- 446 m, 14 Jan 1979, NMNZ Cr 8479. 5 males (SL 7.8 -14.8 mm), 5 females (SL 5.2-8.9 mm), 2 females ovig. (SL 8.5, 8.6 mm), off Westport , RV James Cook, Jl 2/006/78, 42°33'S, 170007'W, 400-473 m, 10 Dec 1978, NMNZ Cr 8448. 1 male (SL 6.3 mm), BS 560, 9.3 mi (17.2 km) S of Kaikoura Light , RV Acheron , 42°35'S, 173°41'E, 640 m, 28 Sep 1976, NMNZ Cr 848l. 3 males (SL 4.2-6.0 mm), 2 females (SL4.8, 4.9 mm), BS 650, northern Mernoo slope, RV Tangaroa, NZOI sta. R 8 , 42°38.2'S, l76°1O.5'E, 999 - 984 m, 11 Jan 1979, NMNZ Cr 8465, 8482. 1 male (SL 4.8 mm), BS 664, Conway Trough, Kaikoura , RV Tangaroa, NZOI sta. R 22 , 42°38.2'S, 173°36.0'E, 632 m, 13 Jan 1979, NMNZ Cr 8480. 1 female ovig. (SL 1l. 9 mm), NW of Chatham Is. , CORl219/89, 42°49.8'S, 177°37.5'W, 815 m, 13 Aug 1989, NMNZ Cr 8455. 10 males (SL 3.6-10.2 mm), 2 females (SL 4.0, 5.2 mm), BS 546, about 24 mi (44.4 km) offWaiau River mouth, RV Acheron , 42°55'S, 173°43'E, 549 -586 m, 18 Mar 1976, NMNZ Cr 8469.5 males (SL 8.3- 1l. 2 mm), 1 female (SL 7.1 mm) , 22 females ovig. (SL 5.9 -8.4 mm), BS 300, Turakirae Trench, 4.5 mi (8.3 km) off Cape Turakirae, 640-658 m, 6 Sep 1972, NMNZ Cr 8439. 1 male (SL 7.8 mm), 3 females (SL 5.5-8.1 mm), 23 females ovig. (SL 6.1- 8.5 mm), Turakirae trench, 2.5 mi (4.6 km) off Cape Turakirae, 640 -658 m, 6 Sep 1972, NMNZ Cr 8445. 1 male (SL 12.2 mm), J09/15/77, 43°13.1'S, 173°51'E, 610 m, 18 Dec 1977, NMNZ Cr 3203.7 males (SL 3.1-6.2 mm), 7 females (SL 3.9-6.4 mm), 29 females ovig. (SL 4.6-5.9 mm), 1 juv. sex indet. (SL 2.2 mm), BS 559, up steep wall of Pegasus Canyon, Pegasus Bay , RV Acheron , 43°14'S, 173°39'E, 1006- 512 m, coral, 27 Sep 1976, NMNZ Cr 8450, 8463. 10 males (SL 4.2- 6.4 mm), 2 females (SL 3.9, 4.8 mm), Taiaroa Trench off Otago Peninsula , RV Acheron , 768- 722 m, 11 Aug 1974, colI. A.I. Black , NMNZ Cr 8474. 3 males (SL 10.3-12.2 mm), 5 females ovig. (SL 9.2- 10.5 mm), Chatham Rise Carea, FV Chiyo Maru, 43°29'S, 176°34'W, 529- 506 m, 15-19 Sep 1987, colI. R . Stewart, NMNZ Cr 8436. 2 males (SL 9.0, 12.5 mm), 1 female (SL 6.9 mm), 4 females ovig. SL 7.2 -8.1 mm), Canterbury Bight , RV James Cook, J9/6/77, 44°40.7, 172°35.5'E, 370- 360 m, 13 Dec 1977, NMNZ Cr 8476. 3 males (SL 8.5-10.5 mm), 2 females ovig. (SL 8.5, 9.6 mm), Canterbury Bight , RV James Cook, 44°44'S, 172°41'E, 402 m, 13 Nov 1970, NMNZ Cr 8440. 2 males (SL 12.2, 12.9 mm), 1 female (SL 10.8 mm), Solander Through, FV Chiyo Maru, haul 149, 46°30'S, 166°14.4'E, 573- 545 m, 10 Sep 1987, NMNZ Cr 8442. 2 males (SL 12.8, 14.4 mm), 1 female ovig. (SL 13.1 mm), Solander Through, FV Chiyo Maru, haul 147, 46°31.9'S, 165°44.4'E, 320 -346 m, colI. R . Stewart, NMNZ Cr 8428, 8434, 8435. 1 male ( SL 12.1 mm), Puysegur Bank, FV Chiyo Maru, Haul 146, 46°44.4'S, 165°43.8'E, 566 - 296 m, 10 Sep 1987, colI. R. Stewart, NMNZ Cr 8449 . 1 female (SL 12.0 mm), S of South Otago, FV Chiyo Maru, H. 156, 47°02.8'S, 169°34.7'E, 309- 331 m, 13 Sep 1987, colI. R . Stewart, NMNZ Cr 8427. 7 males (SL 8.6-14.2 m), 4 females (SL 5.9-12.4 mm), Northern Campbell Plateau , FV Chiyo Maru, H. 155, 47°30.5'S, 169°14.7'E, 529 - 526 m, 13 Sep 1987, colI. R . Stewart, NMNZ Cr 8437, 8443, 8444. 9 males (SL 8.1- 12.2 mm), 5 females (SL 8.7- 11.8 mm), 1 female ovig. (SL 10.4 mm), Snares Is. Shelf , RV James Cook, Jl /22/ 77, 48°12'S, 168°09'E, 700 -706 m, 23 Jan 1977, NMNZ Cr 8457. 1 male (SL 9.7 mm), Snares Is. Shelf , RV James Cook, Jl /24/77, 48°19'S, 167°55'E, 210-292 m, 23 Jan 1977, NMNZ Cr 8432. 1 male (SL 10.2 mm), Snares Is. Shelf , RV James Cook, Jl /19/77, 48°50'S, 167°08'E, 514- 535 m, 22 Jan 1977, NMNZ Cr 8478. 1 male (SL 12.1 mm), Auckland Is. , RV James Cook, 12/16/80, 51°01.4'S, 166°19.2'E, 168 -262 m, 30 Jan 1980, NMNZ Cr 8430.

Diagnosis. First 11 pairs of gills trichobranchiate. Shield usually as broad as long; dorsal surface often weakly calcified medially; rostrum rounded with broad low dorsal ridge; anterior margin concave; lateral projections subtriangular, with small terminal spine; ventrolateral margin unarmed; posterior margin broadly rounded. Ocular peduncles more than half length of shield; ocular acicles ( Fig. 7a,b ) subtriangular, terminating in strong simple or bifid spine; corneae slightly dilated. Sternite of 3rd maxilliped with spine on each side of midline. Epistomial spine short and straight, often absent. Antennular peduncle exceeding distal margin of corneae by nearly full length of ultimate segment. Antennal peduncle at most slightly exceeding distal margin of corneae; 4th segment with small dorsolateral distal spine; 3rd segment with strong ventromesial distal spine; 2nd segment with dorsolateral distal angle produced, terminating in strong multifid spine; acicles sinuous in dorsal view, usually not exceeding distal margin of corneae, mesial margin armed with 13 to 19 strong spines; flagellum distinctly overreaching right cheliped, with numerous setae 1 or 2 flagellar articles in length. Chelipeds markedly dissimilar, covered with moderately dense simple and plumose setae. Right cheliped massive ( Fig. 7 c-e), chela usually operculate; proportions and armature strongly affected by size and sexual dimorphism; fingers strongly curved ventromesially, dactyl with ventromesial face concave; dorsal surface of palm with numerous small tubercles or spines; dorsomesial and dorsolateral margins of palm well delimited by row of spines, dorsolateral margin often strongly curved. Left cheliped well calcified; palm with dorsomesial, dorsolateral, and often dorsomedial rows of small tubercles or spines; carpus with dorsal row of spines. Ambulatory legs usually overreaching extended right cheliped by about 0.25 length of dactyl, armature on meri, carpi and propodi frequently more developed on right than on left; dactyl shorter than propodus, with ventromesial row of 15 to 20 strong spinules, dorsal row of long setae, and 3 or 4 short dorsomesial oblique rows of setae on distally; carpus ( Fig. 7f ) with dorsal row of spines. Anterior lobe of sternite of 3rd pereopods with 1 to 3 small marginal spines, setose. Fourth pereopod ( Fig. 7h,g ) with dactyl terminating in sharp corneous claw; propodal rasp with 2 to 5 irregular rows of ovate scales. Vropods and telson markedly asymmetrical; telson with weak transverse suture, terminal margin separated by shallow, broad V-shaped sinus into unequal lobes armed with short corneous spines. Male 1st gonopods each with moderately concave distal lobe; 2nd gonopods each with distal segment spatulate, basal segment occasionally with short exopod. Females lacking 1st pleopods, or occasionally with rudimentary paired or unpaired 1st pleopods; with vestigial right 2nd pleopod.

Distribution. Southern hemisphere from 22°S to 57°S; in the Atlantic possibly as far north as Ascension Island. Depth: 91 to 1995 m.

Remarks. While examining the numerous material of this species from Australia and New Zealand, extreme variations were observed. The ocular acicles are frequently bifid ( Fig. 7a ). The armature of carpus and chela of the right cheliped, and carpi of walking legs, can be strong ( Fig. 7 c-f). On the 4th pereopod, the propodal rasp frequently exhibits two rows of ovate scales; the dactyl has a much longer, slenderer claw in females than in males ( Fig. 7g,h ). The type of housing used also varies, in some specimens consisting of a gastropod shell, in others of a zoanthid. Variations were particularly pronounced in the New Zealand material, but with such a considerable amount of morphological overlap with specimens from other regions that there is no character, or suite of characters, that can be used to justify separation at the species level.

Figures

Fig. 7. Sympagurus dimorphus (Studer, 1883). a,b, ocular acic1es, dorsal; c-e, carpus and chela of right cheliped: c, male; d, female; e, same, mesial; f, carpus of right 2nd pereopod, lateral; g,h, propodus and dactyl of left 4th pereopods, lateral: g, male; h, female. Scales = 1 mm (a,b,g,h), 4 mm (c), and 2 mm (d,e,f). (New Zealand: a, d-f, female [SL 8.1 mm], NMNZ er 3204; b, male [SL 8.4 mm], NMNZ er 3204; c,g, male [SL 9.2 mm], New Zealand, NMNZ er 8472; h, female [SL 6.9 mm], NMNZ er 3204).