Decapoda - Brachyura - Sesarmidae - Armases

Armases roberti (H. Milne Edwards, 1853)

World Distribution
Chace & Hobbs (1969: 184) - West Indies, Veracruz, Mexico, to San Juan del Norte, Nicaragua; Venezuela (Cuba, Jamaica, Hispaniola, Puerto Rico, Saint Thomas, Saint Croix, Dominica, Martinique, Saint Lucia I., Barbados, Trinidad). I t seems very unlikely, as pointed out by Monod (1956), that S. roberti occurs in West Africa, especially on Gorée Island, the indicated type-locality of the species.

Environnement : Marine & Land - Substrat/Association : Soft bottom (mud or sand)

Vertical range : Intertidal - Min-Max observed: 0-1 m

Lesser Antilles data
Distribution: VGI (St Thomas, St Croix), Lesser Antilles, ICA (Dominica, Guadeloupe, Martinique, St Lucia, Barbados, Trinidad). Terrestrial - Intertidal (mangrove). WA.
Sesarma (Holometopus) roberti - Rathbun, 1918: 312, Dominica, Martinique, St Lucia. - Chace & Hobbs, 1969: 184, St Thomas, St Croix, Dominica, Martinique, St Lucia, Barbados, Trinidad.
Sesarma americana de Saussure, 1857: 305, St Thomas. - Saussure, 1858: 441, Saint Thomas (probably an error cf. Abele, 1992: 38). - Pocock, 1889: 7, Dominica [from Laiou (freshwater); probably Layou River] - Not Armases americanum (Saussure, 1858) but Armases roberti (H. Milne Edwards, 1853) instead; see comment and Abele (1992).
Sesarma (Holometopus) americanum - Chace & Hobbs, 1969: 178, St Thomas - Same, see comment.
Sesarma (Holometopus) angustipes - Rathbun, 1933: 91, St Thomas. Not Sesarma angustipes Dana, 1852, but S. roberti instead (cf. Abele, 1992).
Sesarma (Holometopus) roberti - Chace & Holthuis, 1948: 25, Trinidad [Coll. P.Hummelinck]. - Hagen, 1977: 36, Trinidad. - Vaslet et al., 2013: 245, annex 3, Guadeloupe [from Bourgeois-Lebel 1982, not seen].
Armases (Holometopus) roberti - Carré, 2005: 23, Martinique (also Armases sp.).
Comment: Abele (1992: 38) indicates that 'Armases americanum is similar morphologically and ecologically to A. roberti. They can be easily distinguished by the male gonopods and female gonopores … Reexamination of maternal in various museums has shown all mainland material identified as A. roberti actually to be A. americanum, and all West Indian material identified as A. americanum to be A. roberti. At present A. americanum appears to be absent from the West Indies and A. roberti absent from the mainland.

Armases roberti - Parasram et al. (2021, Zootaxa: 472, fig. 13) - Barbados.
Armases roberti - St Vincent, probably this species (front quadrilobate and cornea green/chartreuse) - 2023, photo transmitted by Holliday.
Armases roberti - St Barthélemy - Photo K. Questel at, consulted 2023.

Comment(s) on data
Abele (1992: 38) - ... Although de Saussure (1858) listed Saint Thomas as the type locality, the species has never been reported from that island. Chace and Hobbs (1969) figured the gonopod of a male syntype of A. americanum leaving no doubt that this is the common mainland species.

References : PDF list, 214 pp (1.4 Mo)

This species in Worms Database