Calcinus gaimardii (H. Milne Edwards, 1848 )

Malay, Maria Celia (Machel) D., Rahayu, Dwi Listyo & Chan, Tin-Yam, 2018, Hermit crabs of the genera Calcinus Dana, Clibanarius Dana, and Dardanus Paul’son from the PANGLAO 2004 Expedition, with description of a new species and a checklist of the hermit crabs of the Philippines (Crustacea: Anomura: Paguroidea), Raffles Bulletin of Zoology 66, pp. 23-65 : 25-27

Calcinus gaimardii (H. Milne Edwards, 1848)

( Fig. 1C )

Pagurus gaimardii H. Milne Edwards, 1848: 68 ( Ambon, Indonesia, type locality).

Calcinus gaimardii – Morgan, 1991: 876–878 (in part, form I), Fig. 13.

Calcinus gaimardii – Rahayu & Forest, 1999: 463–465, Figs. 1A , 2A, B, E, F, I ; Asakura, 2002: 48–52, Figs. 1 A–C, 1H–N, 12–14; McLaughlin et al., 2007: 157–158, 2 unlabelled figures; Malay & Paulay, 2010, Appendix S1.

Material examined. 1 male SL 7.0 mm ( ZRC), stn M1, Alona Beach , Panglao I., 9°32.9′N, 123°46.6′E, 0–1 m, v.2004 to vii.2004; 2 males SL 5.7–7.0 mm ( ZRC), 1 indiv. sex unknown SL 5.4 mm ( ZRC), stn M2, west end of Alona Beach , Panglao I., 9°32.8′N, 123°45.9′E, 0–2 m, 30.v.2004 ; 1 female SL 5.5 mm, 1 male SL 5.5 mm ( ZRC), stn M3, Danao , Panglao I., 9°32.5′/33.1′N, 123°44.7′/45.5′E, 0–2.5 m, 31.v.2004 ; 2 males SL 5.2–5.8 mm ( ZRC), stn M8, Doljo , north coast, Panglao I., 9°35.4′N, 123°44.3′E, 0–1 m, 2.vi.2004 ; 1 female SL 6.6 mm ( ZRC), stn M19, Pamilacan I., 9°30.0′N, 123°55.3′E, 0–2 m, 11.vi.2004 ; 1 male SL 5.2 mm ( ZRC), stn M20, Pamilacan I., 9°29.3′N, 123°55.1′E, 0–2 m, 13.vi.2004 ; 3 ovig. females SL 3.5–7.5 mm, 1 female SL 5.0 mm, 2 males SL 6.5–7.5 mm ( ZRC), stn M22, Napaling , Panglao I., 9°37.2′N, 123°46.4′E, 0–3 m, 15.vi.2004 ; 5 males SL 3.7–6.3 mm ( ZRC), stn R1, Balicasag I., 9°31.2′N, 123°41.3′E, 5–7 m, 30.v.2004 ; 1 male SL 6.0 mm ( ZRC), stn R11, Biking , Panglao I., 9°35.2′N, 123°50.5′E, 4 m, 2.vi.2004 ; 1 female SL 5.6 mm ( ZRC), stn R14, Baclayon , Bohol I., 9°37.4′N, 123°54.5′E, 6–8 m, 3.vi.2004 ; 1 female SL 5.4 mm, 1 male SL 6.6 mm ( ZRC), stn R14, Baclayon , Bohol I., 9°37.4′N, 123°54.5′E, 6–8 m, 3.vi.2004 ; 2 males SL 3.0– 5.1 mm ( ZRC), stn R17, Black Forest , Panglao I., 9°31.1′N, 123°41.3′E, 3–15 m, 4.vi.2004 ; 1 male SL 6.2 mm ( ZRC), stn R21, Rico’s Wall , Panglao I., 9°31.0′N, 123°40.8′E, 2–50 m, 5.vi.2004 ; 1 male SL 6.0 mm ( ZRC), stn R23, lagoon off Poblacion , Panglao I., 9°33.5′/34.8′N, 123°42.7′/46.3′E, 1–5 m, 5, 6, & 21.vi.2004 ; 1 ovig. female SL 4.1 mm ( ZRC), stn R24, Bingag , Panglao I., 9°37.5′N, 123°46.8′E, 0–2 m, 6.vi.2004 ; 2 ovig. females SL 3.5–4.2 mm, 2 males SL 5.8–6.1 mm ( ZRC), stn R24, Bingag , Panglao I., 9°37.5′N, 123°46.8′E ,, 0–2 m, 6.vi.2004 ; 3 ovig. females SL 4.4–5.4 mm, 1 female SL 3.0 mm, 1 male SL 6.8 mm, 1 indiv. in shell ( ZRC), stn R27, Napaling , Panglao I., 9°37.0′N, 123°46.3′E, 2–20 m, 7.vi.2004 ; 1 male SL 6.0 mm ( ZRC), stn R36, Pamilacan I., 9°30.2′N, 123°55.3′E, 3–32 m, 9.vi.2004 ; 1 ovig. female SL 6.2 mm, 4 males SL 5.4–6.8 mm, 3 indivs. in shell ( ZRC), stn R38, Pamilacan I., 9°29.4′N, 123°56.0′E, 6–37 m, 11.vi.2004 ; 1 female SL 5.8 mm ( ZRC), stn R40, Pamilacan I., 9°29.2′N, 123°55.1′E, 8–33 m, 12.vi.2004 ; 1 male SL 6.6 mm ( ZRC), stn R42, Baclayon Takot , Bohol I., 9°37.1′N, 123°52.6′E, 8–22 m, 12.vi.2004 ; 3 males SL 4.8–6.5 mm ( ZRC), stn R43, Cortes Takot , Bohol I., 9°41.3′N, 123°49.5′E, 3–41 m, 13.vi.2004 ; 1 female SL 4.5 mm ( ZRC), stn R70, Pamilacan I., 9°30.1′N, 123°55.5′E, 20 m, 1.vii.2004 ; 1 ovig. female SL 4.4 mm, 6 males SL 3.6–6.0 mm ( ZRC), stn R73, Balicasag I., 9°30.9′N, 123°40.8′E, 2–30 m, 2.vii.2004 ; 1 ovig. female SL 5.7 mm ( ZRC), stn S12, Pamilacan I., 9°29.4′N, 123°56.0′E, 6–8 m, 14.vi.2004 .

Habitat. Intertidal to subtidal, 0–12 m deep, intertidal reef flats, seagrass beds, and reef slopes, on rocky, coralline, sandy, and mixed substrates. This species is typically found in areas sheltered from strong wave action.

Remarks. Calcinus gaimardii closely resembles C. morgani Rahayu & Forest, 1999 , in morphology and colour pattern. Examination of live colour patterns is the most reliable way to separate these two species: the ocular peduncles of C. gaimardii have a narrow blue band distally; proximally the peduncle is orange coloured with a longitudinal tapering dark brown stripe running down the dorsal surface of the peduncle. In C. morgani the distal blue band on the ocular peduncle is broader, and the proximal portion of the ocular peduncle lacks orange colouration. In C. gaimardii dark brown pigmentation covers the shield (either the anterior half or the entire shield is dark coloured), while in C. morgani the entire shield is light-coloured (gray-white to cream). Also, the ambulatory legs and distal portions of the chelae are typically dark brown (light brown to white with brown spots in juvenile) in C. morgani , while the colouration of these areas in C. gaimardii tends towards orange-brown or reddish-brown.

While the two species are sympatric, the geographic range of C. gaimardii (eastern Indian Ocean to Fiji) is more restricted than that of C. morgani (east Africa to Tuamotu; see Malay & Paulay, 2010; Fig. 8 ). In addition, C. gaimardii prefers more wave-sheltered habitats than C. morgani (Asakura, 2002) .

Figures

Fig. 1. A, Calcinus elegans (H. Milne Edwards, 1836). Male SL 10.0 mm, stn M1; B, Calcinus fuscus Malay, Komai & Chan, 2012. Male SL 4.1 mm, stn B42; C, Calcinus gaimardii (H. Milne Edwards, 1848). Female SL 5.6 mm, stn R14; D, Calcinus laevimanus (Randall, 1840). Male SL 4.4 mm, stn M2; E, Calcinus latens (Randall, 1840). Male SL 3.0 mm, stn R1; F, Calcinus lineapropodus Morgan & Forest, 1991. Male SL 4.5 mm, stn R16; G, Calcinus minutus Buitendijk, 1937. Male SL 4.7 mm, stn R10; H, Calcinus morgani Rahayu & Forest, 1999. Female ovig SL 4.8 mm, stn M2.

Fig. 2. A, Calcinus pulcher Forest, 1958. Male SL 4.8 mm, stn R24; B, Clibanarius ambonensis Rahayu & Forest, 1993. Male SL 4.0 mm, stn M16; C, Clibanarius antennatus Rahayu & Forest, 1993. Male SL 3.9 mm, stn M34; D, Clibanarius corallinus (H. Milne Edwards, 1836). Male SL 3.0 mm, stn M58; E, Clibanarius cruentatus (H. Milne Edwards, 1848). Specimen not measured and sexed, Stn M2; F, Clibanarius englaucus Ball & Haig, 1972. Male SL 4.2 mm, stn M1; G, Clibanarius infraspinatus (Hilgendorf, 1869). Male SL 9.0 mm, stn S53; H, Clibanarius laevimanus Buitendijk, 1937. Specimen not measured and sexed, stn M9.

Fig. 8. Dardanus balhibuon, new species, holotype. Female SL 14.3 mm, stn R38, NMCR 40109. A, Left second pereopod, lateral view; B, Propodus of left third pereopod, lateral view. Scale bars = 1 mm.