Color plate 3 B
Material examined. Jamaica: 13 non-ovigerous individuals, 1 ovigerous female, (VIMS 08JAM0901,02), Pear Tree Bottom Reef, from canals of Xestospongia proxima. 61 non-ovigerous individuals, 2 ovigerous females, (VIMS 08JAM 1201 -04), Pear Tree Bottom Reef, from canals of X. proxima. 60 non-ovigerous individuals, 1 ovigerous female, (VIMS 08JAM 5001 -03), Columbus Park, Discovery Bay, from canals of X. proxima. 47 non-ovigerous individuals, 1 ovigerous female, (VIMS 08JAM7401,03,05-07), wall off Rio Bueno, from canals of X. proxima. 47 non-ovigerous individuals, 1 ovigerous female, (VIMS 08JAM7501,07,08), wall off Rio Bueno, from canals of Xestospongia subtriangularis. 58 non-ovigerous individuals, (VIMS 08JAM8406,07), wall off Rio Bueno, from canals of X. proxima. MaxCL ovigerous female: 4.00 mm. MaxCL non-ovigerous individual: 4.83 mm.
Color. Pale milky in appearance, distal end of major chela pale gold/orange. Embryos and ovaries light green.
Hosts and ecology. In Jamaica, this species has only been collected from sponges of the genus Xestospongia, often found cohabitating with other members of the Synalpheus paraneptunus group (S. belizensis, S. bocas). Synalpheus duffyi in Jamaica exhibits a eusocial colony structure, being found in colonies consisting of one or two reproducing females and up to 61 non-ovigerous individuals.
Distribution. Caribbean Panama (Anker and Tóth 2008); Jamaica (this study).
Remarks. Synalpheus duffyi is a member of the complex of morphologically similar species that includes S. paraneptunus, S. belizensis and S. bocas. Synalpheus duffyi can be distinguished from its two coexisting Jamaican relatives by the presence of a well-developed blade on the scaphocerite, and two teeth anterior to the moveable spine on the margin of the uropodal exopod. As mentioned by Anker and Tóth (2008), many individuals of this species had pieces of sponge in the mouthparts, evidence that they may actively feed upon the sponge. Finally, S. duffyi seemed to be the only heavily parasitized species collected in Jamaica: at least 10 % of non-ovigerous individuals harbored large, abdominal bopyrid isopods, which were rarely, if ever, found in individuals of other species.
PLATE 3. A, Synalpheus corallinus non-ovigerous individual (08JAM 7002) from Hyattella intestinalis, Dairy Bull Reef, Jamaica. B, Synalpheus duffyi ovigerous female (08JAM 7403) from Xestospongia proxima, Rio Bueno, Jamaica. C, Synalpheus irie ovigerous female (08JAM 3601) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica. D, Synalpheus irie non-ovigerous individual (08JAM 3602) from Auletta cf. sycinularia, Dairy Bull Reef, Jamaica.