Munida chydaea, Ahyong & Poore, 2004

Ahyong, Shane T. & Poore, Gary C. B., 2004, Deep-water Galatheidae (Crustacea: Decapoda: Anomura) from southern and eastern Australia, Zootaxa 472 (1), pp. 1-76 : 24-28

Munida chydaea n. sp. ( Fig. 4 )

Munida haswelli . — Haig, 1973: 273–274 [part, not M. haswelli Henderson, 1885 ].

Type material. HOLOTYPE: AM P20669, female (36.2 mm), E of Brush Island , New South Wales, 35º28–34’S, 150º48–45’E, 467– 448 m, K75­02­09, K. Graham.

PARATYPES: AM P61823, 1 female (33.0 mm), SE of Ulladulla , New South Wales, 35°34’S, 150°45’E, 543–560 m, K96­24­03, 11 Dec 1996 ; AM P17961, 1 male (32.2 mm), E of Brush Island , New South Wales, 423– 405 m, 35º31–37’S, 150º45–42’E, K71­ 11­10, 8 Jul 1971 ; AM P67289, 1 female (33.1 mm), E of Brush Island , New South Wales, 35º31–28’S, 150º45–47’E, 412 m, K77­21­04, 22 Nov 1977 ; AM P67299, 1 female (32.0 mm), E of Batemans Bay , New South Wales, 35°40’S, 150°41’E, 541–585 m, K96­23­04, 4 Dec 1996 ; AM P31493, 1 male (26.4 mm), E of Brush Island , New South Wales, 35°32’S, 150°46’E, 458 m, K77­21­03, 22 Nov 1977 ; AM P25063, 2 males (34.9–40.0 mm), E of Batemans Bay , New South Wales, 35º32–42’S, 150º39–45’E, 384 m, K76­21­ 11/12, 25 Nov 1976 ; AM P61120, 3 males (34.0– 45.7 mm), off Bermagui , New South Wales, 36º12’S, 150º23’E, 348 m, 17 Feb 2000 .

Other material examined. NEW SOUTH WALES: AM P53250, 1 female (31.0 mm), E of Broken Bay , 33º34’S, 152º02’E, 662 m, K86­01­06, 11 Feb 1986 ; AM P21013, 1 ovigerous female (27.1 mm), E of Broken Bay , 33º25–30’S, 152º03–07’E, 641 m, K75­ 05­04, 19 Aug 1975 ; AM P66656, 1 female (31.0 mm), E of Port Jackson , 33°49’S, 151°54’E, 450 m, 5 May 1978 ; AM P66653, 2 males (31.5–32.0 mm), 1 female (32.8 mm), NE of Wollongong , 34º18’S, 151º26’E, 457–467 m, K75­05­06, 20 Aug 1975 ; AM P21105, 1 male (28.0 mm), 2 ovigerous females (31.1–31.6 mm), NE of Wollongong , 34º16–22’S, 151º26–23’E, 366 m, K75­05­01, 8 Aug 1975 ; AM P31503, 1 female (34.9 mm), NE of Wollongong , 439 m, K78­08­02, 24 May 1978 ; AM P21055, 1 male (35.0 mm), 5 ovigerous females (27.0– 34.1 mm), NE of Wollongong , 34º21–14’S, 151º24– 28’E, 403 m, K75­05­02, 8 Aug 1975 ; AM P21052, 5 males (24.0– 39.1 mm), 6 females (2 ovigerous) (24.0– 34.1 mm), E of Port Kembla , 34º28–34’S, 151º19–17’E, 412 m, K75­05­ 07, 20 Aug 1975 ; AM P19392, 2 males (23.9–30.6 mm), E of Kiama , 34º40–45’S, 151º14–12’E, 378– 342 m, K71­11­02, 6 Jul 1971 ; AM P20747, 1 female (26.0 mm), E of Kiama , 34º38–46’S, 151º15–13’E, 458– 439 m, K75­02­17, 30 Jun 1975 ; AM P20746, 1 female (36.1 mm), E of Shoalhaven , 34º49–56’S, 151º10–09’E, K75­01­18, 30 Jun 1975 ; AM P31487, 7 males (23.5–32.8 mm), 6 females (23.1–30.0 mm), E of Beecroft Head , 35°00’S, 151°07’E, 414 m, K79­03­18, 26 Apr 1979 ; AM P53246, 1 male (28.4 mm), E of Shoalhaven River , 32º02’S, 151º06’E, 366 m, K79­11­09, 9 Aug 1979 .

VICTORIA: AM E4781 , 1 male (23.3 mm), off Gabo Island , 146–183 m, 1913 ; AM P61122, 1 male (33.8 mm), SE of Gabo Island , 37º41’S, 150º15’E, 384 m, K77­10­06, 13 Jul 1977 ; AM P20805, 1 female (12.4 mm), SE of Gabo Island , 37º45–38’S, 150º12–16’E, 403–439 m, K75­03­02, 10 Jul 1975 ; AM P20812, 1 male (25.4 mm), SE of Gabo Island , 37º36–40’S, 150º15–14’E, 348–366 m, K75­03­03, 11 Jul 1975 ; AM P61821, 2 males (35.0–38.0 mm), SE of Gabo Island , 37°38’S, 150°14’E, 322–331 m, K96­12­05, K, Graham, 24 Jul 1996 ; AM P61822, 2 males (24.1–28.0 mm), 2 females (21.9–31.0mm), SE of Gabo Island , 37º38–40’S, 150º14–13’E, 316–327 m, K96­21­03, 22 Oct 1996 ; AM P61824, 1 female (27.5 mm), off Gabo Island , 37°39’S, 150°16’E, 437–444 m, K97­01­ 18, 29 Apr 1997 ; AM P61820, 2 females (19.0– 31.6 mm), SE of Gabo Island , 37º39’S, 150º16’E, 448 m, K96­21­18, 31 Oct 1996 ; AM P61123, 1 male (34.9 mm), off Portland , 38º30’S, 141º45’E, 403 m, 13 Nov 1999 ; NMV J52076 , 1 male (26.0 mm), 38°12.57’S, 149°37.33’E, 382 m, SS01/00/184, 21 Apr 2000 ; NMV J52047 , 2 males (18.0– 21.5 mm), 38°13.78’S, 149°36.99’E, 435 m, SS01/00/197, 22 Apr 2000 ; NMV J52048 , 6 males (17.0–32.0 mm), 1 female (16.0 mm), 38°15.07’S, 149°38.65’E, 525 m, SS01/00/241, 26 Apr 2000 ; NMV J52052 , 2 males (13.5–19.8 mm), 3 females (22.2–28.2 mm), 38°14.73’S, 149°42.01’E, 503 m, SS01/00/188, 21 Apr 2000 ; NMV J52049 , 2 males (14.5–21.0 mm), 6 females (19.4–27.0 mm), 38°14.91’S, 149°38.67’E, 500 m, SS01/00/ 187, 21 Apr 2000 .

TASMANIA: AM E5175 , 3 males (14.9–31.1mm), 5 females (19.0– 33.7 mm), ENE of Maria Island , 232–329 m, 1914 ; AM P60188, 1 male (34.0 mm), E of Fortescue Bay , 43º07.36’S, 145º13.75’E, 400 m, TAS­381, J. Lowry et al., 17 Apr 1993 ; AM P60189, 1 female (17.8 mm), E of Fortescue Bay , 43º07.36’S, 145º13.75’E, 400 m, TAS­416, J. Lowry et al., 9 Apr 1993 ; AM P60191, 1 female (28.8 mm), E of Fortescue Bay , 43º09.39’S, 145º13.60’E, 300 m, TAS­397, J. Lowry et al., 8 Apr 1994 ; AM E5154 , 2 females (26.9–33.1 mm), 56.3 km SE of Bruny Island, D’Entrecasteaux Channel , 275–421 m, 1914 ; SAM C6057 , 2 males (38.0– 36.5 mm), 22.2 km ESE of Mistaken Cape, Maria Island , 42°42’S, 148°25’E, 338–700 m, epibenthic sled, SS06/96/241, 18 Dec 1996 ; SAM C6058 , 32 males (7.6–29.8 mm), 37 females (10.5–31.5 mm), 38.9 km W of Granville Harbour , 41°51’S, 149°33’E, 425 m, epibenthic sled, W. Zeidler, 20 Oct 1984 .

SOUTH AUSTRALIA: AM E3688 , 1 male (42.0 mm), Great Australian Bight , ESE of Eucla, 126º45’E, 457–548 m, FIS Endeavour, 1909–1914 .

Diagnosis. Carapace with oblique frontal margins; transverse ridges closely spaced, mostly uninterrupted; with pair of epigastric spines followed by pair of protogastric spines and numerous spinules on anterior quarter of carapace in addition to paired parahepatic, paired anterior branchial and paired postcervical spines. Rostrum spiniform, about twothirds remaining carapace length. Margins of carapace with 5 spines posterior to cervical groove. Fourth and fifth sternites with several short, granular striae; sixth and seventh sternites smooth. Second tergite with row of 8–11 spines on anterior border. Third tergite with 1 or 2 (usually 2) submedian spines on anterior border. Eyes large, with maximum corneal diameter about one­third basal distance between anterolateral spines. Antennular basal segment elongate with distomesial spine longer than distolateral spine. Antennal basal segment of peduncle with strong mesial spine; second segment with spine on mesial margin, and with mesial and lateral terminal spines, mesial overreaching distal segment of peduncle; third segment with 2 outer spinules; fourth segment with 1 outer spinule. Cheliped slender, 2–3 times carapace length. Pereopod 2–4 merus with spinose extensor and flexor margins; dactylus with ventral movable spines on proximal three­quarters.

Description. Carapace: Transverse ridges closely spaced, mostly uninterrupted; cervical groove distinct; with pair of epigastric spines followed by pair of protogastric spines; with numerous spinules on anterior quarter of carapace in addition to paired parahepatic, paired anterior branchial and paired postcervical spines. Frontal margins oblique; rostrum spiniform, faintly upcurved, about twice as long as supraocular spines and about twothirds remaining carapace length. Supraocular spines subparallel or slightly divergent. Anterolateral spine well developed, situated at anterolateral angle, extending to or slightly beyond sinus between rostrum and supraocular spine. Margins of carapace anterior to cervical groove with 2 or 3 spines (including anterolateral) and 1 or 2 spinules; with 5 spines posterior to cervical groove.

Sternum: Fourth and fifth sternites with several short, granular striae; sixth and seventh sternites smooth; ridges demarcating fourth to seventh sternites feebly granular.

Abdomen: Second tergite with row of 8–11 spines on anterior border. Third tergite with 1 or 2 (usually 2) submedian spines on anterior border. Second and third tergites with 5 uninterrupted transverse striae. Fourth tergite with 2 uninterrupted transverse striae alternating with 2 medially interrupted striae.

Eye: Large, with maximum corneal diameter about one­third basal distance between anterolateral spines; peduncle with row of short distal setae (‘eyelashes’).

Antennule: Basal segment elongate, overreaching cornea; with 2 terminal spines, mesial longer; with two lateral spines, distal markedly longer than proximal.

Antenna: Basal segment of peduncle with strong mesial spine. Second segment with spine on mesial margin and with mesial and lateral terminal spines, mesial overreaching distal segment of peduncle; outer margin with 1 or 2 short striae. Third segment of antennal peduncle with 2 outer spinules; fourth segment with 1 outer spinule.

Maxilliped 3: Ischium with strong distal flexor spine. Flexor margin of merus with distal and proximal spine, proximal largest; extensor margin unarmed.

Pereopod 1 (cheliped): Slender, 2–3 times carapace length; squamous and setose, setae densest dorsally. Dactylus with small dorsal proximal spine and 2 or 3 small subterminal spines; occlusal margin denticulate. Propodus with upper and outer margin spinose; palm about 5 times as long as high, longer than pollex; pollex with 2 or 3 subterminal spines, dorsally unarmed, occlusal margin denticulate. Carpus and merus with irregularly distributed spines on lateral, dorsal and mesial surfaces; spines strongest distally.

Pereopod 2: Merus extensor margin with 7–12 spines; flexor margin with 4–6 ventral spines. Carpus with 3–6 extensor and 1 flexor spine. Propodus flexor margin with 12–15 spines. Dactylus half to two­thirds propodus length; flexor margin with 12–17 movable spines; terminal quarter unarmed.

Pereopod 3: Merus extensor margin with 7–11 spines; flexor margin with 4–7 spines. Carpus with 2–5 extensor and 1 flexor spine. Propodus flexor margin with 10–15 spines. Dactylus half to two­thirds propodus length; flexor margin with 10–17 movable spines; terminal quarter unarmed.

Pereopod 4: Merus extensor margin with 1–4 spines; flexor margin with 2 or 3 spines on distal third. Carpus with 2–5 extensor and 1 flexor spine. Propodus flexor margin with 7–12 spines. Dactylus half to three­quarters propodus length; flexor margin with 8–12 movable spines; terminal quarter unarmed.

Etymology. Derived from the Latin chydaeus, meaning ‘abundant,’ alluding to the abundance of the present species.

Remarks. Munida chydaea n. sp. most closely resembles M. gracilis Henderson, 1885 from eastern New Zealand but differs in the following features: the flexor margin of the dactylus of the first walking leg is unarmed for the distal quarter instead of distal third; the third and fourth antennal segments bear an outer spinule; the anterior margin of the third abdominal tergite bears 1 or 2 (usually 2) instead of 4 spines; and the second and third abdominal tergites bear more numerous transverse striae. Although the number of transverse striae on the abdominal tergites increases with size, the smallest specimen of M. chydaea (cl. 12.4 mm, ocl. 6.7 mm) bears 2 and 3 instead of 1 and 2 striae on the second and third tergites respectively as in the syntype of M. gracilis (ocl. 6.8 mm) figured by Macpherson (1994: fig. 19).

The present specimens are similar but differ chiefly in the degree of spination on the anterior portion of the carapace, and in setation and size of spines on the pereopods. The number of spinules on the anterior portion of the carapace between and adjacent to the epigastric and protogastric spines increases with size. Similarly, the setation of the pereopods is densest in the largest specimens and the relative size of the spines decreases with increasing size. Additional variation is present in the following features: the first segment of the antennal peduncle usually bears short striae, of which one is occasionally produced to a minute spinule; the third segment of the antennal peduncle usually bears 2 small outer distal spinules, but the dorsalmost of these may be obsolete or present as a tubercle; the number of spines on the anterior margin of the second abdominal tergite varies from 8–11.

Munida chydaea is frequently sympatric with M. haswelli with which it has sometimes been misidentified. The two species are most readily distinguished by the spination of the anterior margin of the third abdominal tergite and presence of numerous short striae on the thoracic sternites in M. haswelli . In M. chydaea , the few short striae that are present are restricted to the fourth and fifth sternites. Munida chydaea also appears to attain a larger body size than M haswelli . The largest specimen of M. haswelli that we have examined measures 21.6 mm cl., whereas M. chydaea attains approximately twice that size. Additionally, M. haswelli is ovigerous by 13.2 mm cl., whereas the smallest ovigerous specimen of M. chydaea is 27.0 mm cl.

Distribution. Sydney area to Victoria, Tasmania and the Great Australian Bight at 146–700 m depth.

Figures

FIGURE 4. Munida chydaea n. sp., holotype female (36.2 mm), AM P20669. A, dorsum. B, left basal antennular segment, ventral. C, left antennal peduncle, ventral. D, right third maxilliped, lateral. E, right cheliped. F, right cheliped, distal portion. G–I, right pereopods 2–4, dorsal. J, sternum. Scale A, E, G–I = 5 mm, B–D, F, J = 2.5 mm.