Agononida incerta ( Henderson, 1888 )

Macpherson, Enrique & Baba, Keiji, 2009, New species of squat lobsters of the genera Agononida and Paramunida (Crustacea: Decapoda: Anomura: Galatheidae) from the western Pacific, Zootaxa 2024, pp. 56-68 : 57-60

Agononida incerta ( Henderson, 1888)

( Figs. 1 , 2 A–E, G–H)

Munida incerta Henderson, 1888: 130 , pl. 13, figs 4, 4a ( Philippines, off Sibago Island (off Zamboanga), 458 m). — Miyake, 1982: 146, pl. 49, fig. 5 (Kumanonada, Japan, 200–300 m). — Baba in Baba et al., 1986: 171, 290, fig. 121 (Okinawa Trough and Tosa Bay, 325–440 m). — Tirmizi & Javed, 1993: 100, figs 43, 44 (eastern Indian Ocean, depth, unknown). — Macpherson, 1994: 478 (part) ( New Caledonia, 580–590 m) (not fig. 74 [= A. rubrizonata from New Caledonia]). — Wu et al., 1998: 113 (part), figs 23, 26D, (not 26E [= A. rubrizonata n. sp.]) ( Taiwan, depths unknown).

Agononida incerta . — Baba & de Saint Laurent, 1996: 442 (new combination). — Macpherson, 1997: 600 (part) ( Indonesia, 307–311 m). — Konishi & Saito, 2000: 1022, figs 1–2 (larvae) (Makurazaki, Kagoshima Prefecture, Japan, 300 m). — Ahyong & Poore, 2004: 8 (Queensland and New South Wales, 150–548 m). — Macpherson, 2004: 241 (part) ( Fiji and Tonga, 500–614 m). — Baba, 2005: 69, 235 (off Durban, Bali Sea, and Kei Islands, 200–458 m). — Poore et al., 2008: 18 (SW Australia, 324–754 m). — Baba et al., 2008: 48 .

Material examined. TAIWAN. Su-ao, Yilan County, NE Taiwan, commercial trawl, 22.05.1990: 3 males (10.8–14.0 mm), 1 ovigerous female (15.5 mm), 2 females (13.1, 15.8 mm) ( NTOU 00483). — 20.08. 1991, 300 m, sandy mud: 1 male (20.8 mm) ( NTOU A00485). — 05.12.1991: 1 male (18.3 mm), 1 female (18.2 mm) ( NTOU A00874 ). — 17.06.1993: 4 male (15.6–19.0 mm), 1 ovigerous female (17.6 mm), 1 female (18.2 mm) ( NTOU A00488 ). — 0 7.08.1996, ca. 350 m: 2 males (20.3, 21.8 mm) ( NTOU A00875 ). — 27.08.1996: 1 male (19.6 mm) ( NTOU 00736). — 0 5.12.1997, ca. 500 m: 2 males (14.6, 17.2 mm) ( NTOU A00876 ). — 29.07.2004: 1 male (21.9 mm), 1 female (24.6 mm) ( NTOU A00878 ). — 10.03.2005: 2 males (9.1, 9.2 mm), 1 female (17.1 mm) ( NTOU A00879 ). Donggang, Pingtung County, 03.06.1995: 2 males (17.2, 17.3 mm) ( NTOU A00495 ). S Taiwan, CD140, 22°11.4’N, 120°22.58’E, 452– 280 m, 23.11.2001: 2 males (16.4, 19.1) mm, 3 ovigerous females (20.7–21.7 mm) ( NTOU A00880 ). — CD141, 22°12.04’N, 119°59.96’E, 1110– 985 m, coral fans and antique pot, 24.11.2001: 1 male (18.0 mm) ( NTOU A00881 ).

PHILIPPINES. Th. Mortensen's Pacific Expedition 1914–16, 25 miles E by S of Zamboanga, 293–366 m, hard bottom, 03.03.1914: 2 males (22.8–35.6 mm), 4 females (12.5–20.5 mm) (ZMUC-CRU-11555). — Th. Mortensen's Pacific Expedition 1914–16, 25 miles E of Zamboanga, 458 m, 04.03.1914: 1 male (10.2 mm) (ZMUC-CRU-11576).

INDONESIA. KARUBAR Stn CP33, 06º05’S, 132º38’E, 27.10.1991, 307– 311 m: 2 males (14.4–15.3 mm), 1 female (8.0 mm) (MNHN-Ga 6687).

NEW CALEDONIA. CORAIL 2 Stn DE 15, 20º50.72’S, 160º55.76’E, 21.07.1988, 580– 590 m: 3 males (15.0– 16.2 mm), 10 ovigerous females (19.6–25.4 mm), 3 females (15.7–16.6 mm) (MNHN-Ga 2724).

FIJI. MUSORSTOM 10 Stn 1341, 16º52.51’S, 177º43.66’E, 10.08.1998, 500– 614 m: 4 males (13.8–16.7 mm), 1 ovigerous female (29.8 mm) (MNHN-Ga 6688).

Description. Carapace as long as wide. Dorsal surface with numerous short striae and transverse ridges usually interrupted in cardiac and branchial regions, with dense, short non-iridescent setae. Gastric region with 2 epigastric spines; 3 postcervical spines (last one occasionally obsolete) on each side, decreasing in size posteriorly. Posterior border of carapace unarmed. Frontal margins slightly oblique. Lateral margins slightly convex. Anterior-most (first) spine strong, situated at anterolateral angle, usually reaching level of sinus between rostrum and supraocular spines; second spine in front of cervical groove small, one-fourth length of preceding one; third to sixth on branchial margin, fourth and fifth slightly larger than third and sixth. Rostrum spiniform, 0.4 postorbital carapace length, nearly straight and horizontal. Supraocular spines horizontal in profile, slightly thicker than rostral spine, clearly overreaching midlength of rostral spine and slightly exceeding ends of corneas.

Thoracic sternites with numerous short striae. Anterior part of fourth sternite narrower than third sternite, contiguous to median part of posterior margin of third sternite. Transverse ridges on fifth, sixth and seventh sternites obtuse, feebly granulated.

Second to fourth abdominal somites squamate, with 4 spines on anterior ridge; posterior ridge of fourth somite with median spine. Telson with numerous scales; no lateral process in males.

Eyes large, maximum corneal diameter about 0.3 times distance between bases of anterolateral spines.

Basal segment of antennule (distal spines excluded) about 0.3 carapace length, elongate, overreaching corneae, with 2 distal spines (mesial spine clearly longer than lateral spine) and with 2 lateral spines, proximal one small, distal one reaching end of distolateral spine. First segment of antennal peduncle with long distomesial process clearly overreaching end of antennular and antennal peduncles. Second segment with strong distomesial spine exceeding third segment, accompanying small mesial spine at base; distolateral spine smaller than distomesial. Third and fourth segments unarmed.

Mxp3 ischium about twice length of merus measured along dorsal margin, with well-developed spine on flexor distal margin. Merus with well-developed spine on flexor median margin and long spine on extensor distal margin.

P1 squamous, with sparse uniramous and plumose setae and iridescent setae on mesial borders of merus and carpus, 3.5–4.0 times carapace length; merus 1.5–1.8 times carapace length, carpus 4 times longer than broad and slightly longer than palm; palm 4–5 times longer than broad and 0.7–1.2 times fingers length. Merus armed with row of spines on mesial, ventral and dorsal borders. Carpus and palm with some spines on lateral, dorsal and mesial margins, some of them absent in large specimens. Fingers unarmed, each with longitudinal carina dorsally and ventrally, distally incurved; fixed finger with 2 terminal spines accommodating opposite terminal spine of movable finger when closed.

P2 3.4–3.8 times carapace length; merus 1.4–1.7 times longer than carapace, 6–10 times long as high, 3.5–4.5 times carpus length and 1.6–1.8 times as long as propodus; propodus 6–10 times long as high, 1.4–1.7 times dactylus length; propodus, when extended forward, reaching or slightly overreaching end of P1 merus. Merus with proximally diminishing spines along dorsal and ventral borders, distal spine strong. Carpus with strong extensor and flexor spine distally, and 1 or 2 additional small extensor marginal spines. Propodus with row of movable spinules on flexor margin. Dactylus slightly curving distally, flexor margin slightly curving, with 9–12 movable spinules in proximal half, unarmed in distal half. P3 as long as P2, and slightly longer than P4; armature and article proportions of P3 and P4 quite similar to those of P2. Dense long iridescent and noniridescent setae along dorsal border of merus and extensor margin of carpus; daclyli with setae along flexor margin, movable spinules reduced in number or obsolescent.

Colour in life. Ground colour of carapace, second to fourth abdominal somites and pereopods pale orange. Pereopods without red bands.

Remarks. The species was described by Henderson (1888) from a female (BMNH 1888:33) collected in the Philippines, off Sibago Island (off Zamboanga), 06º47’N, 122º28’E, 458 m depth. Unfortunately, the holotype is actually damaged and incomplete so that topotypic material including males from off Zanboanga, Philippines, was examined and included in the description.

The unusual form in A. incerta that bears a lateral process on the male telson and red bands on P1–4 ( Baba 1994; Macpherson 1994; Ahyong & Poore 2004) is described as A. rubrizonata n. sp. (see below). The true A. incerta is now defined as having no outward process on the anterior lateral expansion of the telson in males and no red bands on P1–4. The synonymy of A. incerta (see above) lists only the verified records, and the remainder of the previous records needs confirmation. Preserved male specimens are easily identifiable but female specimens are not. The colorations only help identify females of A. incerta and A. rubrizonata .

The occurrences, at least in part, to be confirmed are the following: Barnard (1925, 1950), Yanagita (1943), Tirmizi (1966), Baba (1988, 1990), Macpherson (1994, 1996, 1997, 1999, 2004) (see Baba et al. 2008, for localities).

Macpherson (1994) and Ahyong & Poore (2004) noted several additional morphological differences between the two forms (= A. incerta and A. rubrizonata ), in the shape and armature of P1. However, our material shows that these differences are not consistent.

Distribution. The species has been collected in the Philippines, Indonesia, Taiwan, Japan, New Caledonia, Fiji, New South Wales, and Queensland, between 150 and 600 m. The specimens identified as A. incerta in previous papers are relatively abundant around the Philippines, Indonesia, Vanuatu, New Caledonia, Fiji, Tonga, Kiribati and Wallis and Futuna, Australia and eastern Indian Ocean (see Baba et al. 2008), where the new species ( A. rubrizonata ) is probably present (see below). This abundant material has not been reviewed in the present paper. A complete study of this material, as well as the other occurrences is needed in order to clarify the geographical distribution of both species.

Figures

FIGURE 1. Agononida incerta (Henderson, 1888). Male, 35.6 mm (ZMUC-CRU- 11555). Philippines, off Zamboanga. Carapace and abdomen, dorsal. Scale: 8 mm.

FIGURE 2. Agononida incerta (Henderson, 1888). A – D, G – H: male, 35.6 mm (ZMUC-CRU- 11555). Philippines, off Zamboanga. E, male, 21.8 mm, Taiwan (NTOU A 00875). F, A. rubrizonata n. sp., male, 25.6 mm, Taiwan (NTOU A 00883). A, telson, dorsal. B, sternum. C, left antennule and antenna, ventral. D, ischium and merus of right third maxilliped, lateral. E-F, merus right P 1, dorsal. G, merus right P 4, lateral. H, carpus, propodus and dactylus right P 4, lateral. Scale: = 4 mm.