Allogalathea elegans ( Adams & White, 1848 )

Silambarasan, Krishnan, Kar, Annada Bhusan, Prasad, Gummadi Venkata Ankineedu, Pattnayak, Sujit Kumar, Das, Pratyush, Reddy, Dwarampudi Bhami & Ramalingam, Lakshmana Perumal, 2023, On some commensal anomuran and brachyuran crabs (Crustacea: Decapoda) off Visakhapatnam, Northwestern Bay of Bengal, Zootaxa 5325 (4), pp. 541-555 : 544

Allogalathea elegans ( Adams & White, 1848)

( Fig. 3A )

Restricted synonymy:

Galathea elegans Adams & White, 1848 : pl. 12 fig. 7.

Allogalathea elegans .— Baba, 1969: 6, fig. 1 (in part).— Haig, 1974: 447 (in part).— Ahyong, 2007: 13 .— Poore et al., 2008: 18, unnumbered photo.— Baba et al., 2009: 53, fig. 2B.— Poore et al., 2011: pl. 3D.— Schnabel et al., 2011: 157.— Cabezas et al., 2011: 256, fig. 2, 3.— Kumaralingam et al., 2015: 268, fig. 27.— Prakash & Marimuthu, 2020: 94 .— Patel et al. 2022: 15.

Material examined. FSI/ CRUST: 231, 1 female (CL 1.8 mm, TL 6.0 mm), 17°40.6’N, 83°53.5’E, 48–49 m, on soft tree coral Dendronephthya sp. , coll. K. Silambarasan, 15 December 2019 .

Distribution. Mozambique, Japan, Thailand, Indonesia, Australia, Vanuatu, New Caledonia and Chesterfield Islands, Tasman Sea ( Ahyong 2007; Cabezas et al. 2011) and India ( Patel et al. 2022); now from Visakhapatnam as the first report from mainland coast.

Commensalism. Allogalathea elegans has previously been reported from different crinoids hosts ( Cabezas et al. 2011). Recently, Prakash & Marimuthu (2020) documented the occurrence of A. elegans on crinoids from Lakshadweep waters such as Stephanometra indica and S. tenuipinna , while Kumaralingam et al. (2015) recorded A. elegans from coral reefs of the Andamans but did not mention about the specific host. Our specimen was collected from Dendronephthya sp. , a soft tree coral off Visakhapatnam.

Remarks. Allogalathea elegans is similar to A. babai . The second to fourth periopods are shorter and more slender in A. elegans compared to A. babai . The merus of the second and third pereiopods is usually unarmed or sometimes with small spines in A. elegans compared to A. babai . The dorsal margin of the merus on the second to third pereiopods has well developed spines. The squamae of the dorsal side of the first pereiopod have several spinules and numerous long setae in A. babai . In A. elegans , only one spinule is on the squamae and a few long setae are present. The epipods is usually present on the first pereiopod in A. elegans instead of always present on the first pereiopods and sometimes present on second and third pereiopods in A. babai .

Figures

FIGURE 3. Anomura associated with cnidarians and poriferans collected from Northwestern Bay of Bengal: A, Allogalathea elegans (Adams & White, 1848); B, Petrolisthes lamarckii (Leach, 1820); C, Porcellanella triloba White, 1851; D, Polyonyx hendersoni Southwell, 1909; E, Pisidia gordoni (Johnson, 1970).