(Fig. 10A–E)
Calappa galloides Stimpson, 1859: 71 [Type locality: Florida Keys].
Trindade specimens. 1 juvenile male (MZUSP 33818), Brazil, off Espírito Santo, Trindade Island, Ponta da Calheta, 20°30’18.72”S, 29°18’31.67”W, J.B. Mendonça coll., 22.x.2014, 15.8 m. 1 male (MZUSP 33815), ibidem, 4.viii.2015, tangle net set over the bottom, 15.8 m.
Size of largest male: cl 28 mm, cw 38 mm.
Comparative material examined. Calappa galloides: Panama: 1 male (USNM 43996), Caribbean Sea, Colón, Limon Bay, coral reef, M. Hildebrand coll., 2.v.1911 [M. J. Rathbun det.]. Brazil: Paraíba: 1 male (MZUSP 5921), Projeto Algas, stn 12C, 7°28’S, 34°34’W, 6.v.1981, 30 m. 1 male (MZUSP 5932), ibidem, stn 29D, 7°15’S, 34°36’W, 2.iv.1981, 28 m. Bahia: 1 male (MZUSP 41411), Minerva Seamount, 17°03.108’S, 37°37.216’W, J. Coltro coll., 12.viii.2012, 69 m. Espírito Santo: 1 male (MZUSP 8018), Serra, Jacaraípe, J.L. Helher coll., iii.1973. Rio de janeiro: 1 female (MZUSP 9428), Ilha Grande, 105 m. São Paulo: 2 males (MZUSP 13766), Ubatuba, Ilha Anchieta, F. Figueiredo coll., ii.1977. 1 male (MZUSP 1696), São Sebastião, Ilha Bela, 6.iii.1962. Central Atlantic: Ascension Island: 1 juvenile female (USNM 256594), offshore Georgetown, Pierhead, bottom net, M. Macdowell, coll., iii.1980, dead coral, 122–152 m [R. B. Manning det.], 1 juvenile male (USNM 256592), off Pyramid Point, 7°54’29.9S, 14°24’36.0”W, C.C. Koenig, 5.viii.1980, 27 m.
Distribution. Amphi-Atlantic. Western Atlantic: from Bermuda and Florida to Brazil (Maranhão, Ceará, Paraíba, Pernambuco, Alagoas, Bahia, Espírito Santo, Rio de Janeiro, São Paulo, Santa Catarina and Rio Grande do Sul). Brazilian oceanic islands: Rocas Atoll, Fernando de Noronha and Trindade (Coelho Filho 2006; Alves et al. 2008). This is the first record of Calappa galloides from Trindade. Central Atlantic: Ascension and Saint Helena (Manning & Chace 1990; Galil 1997). Eastern Atlantic: Canary Islands, Cape Verde and scattered localities between Senegal and Angola, including São Tomé and Principe in the Gulf of Guinea (González 2018; González et al. 2000). Calappa galloides is also known from the Pliocene of Curaçao (Luque et al. 2017).
Ecological notes. Known from the shore down to 220 m in hard substrates including reefs, maërl and cobble beds, coral, sand, slightly muddy sand, shell, and rocks (Keith 1985; Manning & Chace 1990; González et al. 2000). In Trindade C. galloides was found in sandy bottoms near boulders. The carapace of a large female (MZUSP 9428) from Rio de Janeiro was fouled with oyster.
Remarks. Manning & Chace (1990) assigned the western Atlantic specimens formerly identified with Calappa gallus (Herbst, 1803) to C. galloides. Calappa gallus is now considered an Indo-West Pacific species (see also Galil 1997). The Trindade specimens (as well as the material from coastal Brazil) agree in all respects with the diagnostic features of C. galloides. The relative width of the carapace is indeed a reliable way of distinguishing this species from C. gallus, whose carapace length is equal to the width ahead of the clypeiform expansion, whereas in C. galloides the carapace length is less than the width ahead of the clypeiform expansion (Manning & Chace 1990) (Fig. 10A).
The female USNM 112522 from Saint Helena Island assigned to Calappa bicornis Miers, 1884, by Manning & Chace (1990) (originally referred to as C. gallus by Chace, 1966) was reidentified as C. galloides by Galil (1997). Calappa bicornis and C. galloides differs from each other in that the front is projected into two triangular teeth separated by a deep sulcus in the former species (Galil 1997), whereas the front is cut into four broad lobes, separated by shallow sinuses in C. galloides (Fig. 10A, C–E).
Holthuis (2001) expressed the possibility that C. tuerkayana Pastore, 1995 (Mediterranean and eastern Atlantic, including the Azores), might be synonymous with C. galloides (as C. gallus), whereas d’Udekem D’Acoz (2001) and Garcia (2002) opined that the differences in color and morphology (carapace ornamentation and shape of the sixth pleonal somite) warrant the recognition of C. tuerkayana as a valid species. Recently, however, Innocenti et al. (2021) put molecular and morphological evidences together to argument that C. tuerkayana is actually a juvenile stage of C. granulata (Linnaeus, 1758).
The specimen from Ubatuba (São Paulo, Brazil) sequenced by Mantelatto et al. (2020) and referred to as Calappa gallus (GenBank: CCDB 5916—COI, MT623341) is most probably referable to C. galloides.