Gnathophyllum americanum Guérin-Méneville, 1855

Tavares, Marcos Domingos Siqueira, Carvalho, Leina & Mendonça Jr., Joel Braga de, 2017, Towards a review of the decapod crustacea from the remote oceanic archipelago of Trindade and Martin Vaz, south Atlantic Ocean: new records and notes on ecology and zoogeography, Papéis Avulsos de Zoologia (São Paulo) 57 (14), pp. 157-176 : 163-164

Gnathophyllum americanum Guérin-Méneville, 1855

( Figure 3 A-B)

Material examined: Brazil: Trindade Island , Enseada Orelhas, 20°29’40.2”S / 29°20’32.9”W, depth: 14 m, J.B. Mendonça coll., 06.vii.2013: 1 male ( MZUSP 31190 ) . Ibidem , depth: 15.4 m, J.B. Mendonça coll., 24.x.2014: 2 males ( MZUSP 33425 ) . Trindade Island , Enseada Orelhas, 20°29’40.2”S / 29°20’32.9”W, depth: 12 m, J.B. Mendonça coll., 01.x.2014: 1 male ( MZUSP 33426 ) . Ibidem , depth: 12.1 m, J.B. Mendonça coll., 18.iv.2014: 1 male ( MZUSP 33428 ) . Trindade Island , Farol (Enseada dos Portugueses), 20°29’52.3”S / 29°19’15.6”W, depth: 12 m, J.B. Mendonça coll., 15.vii.2013: 1 male ( MZUSP 31184 ) . Trindade Island , Praia do Andrada, 20°30’71.8”S/ 29°18’24.7”W, depth: 9.9 m, J.B. Mendonça coll., 17.vii.2013: 1 ovigerous female ( MZUSP 31187 ) . Trindade Island , Ilha da Racha, 20°30’26.5”S / 29°20’48.0”W, depth: 30.3 m, J.B. Mendonça coll., 12.vii.2012: 1 male ( MZUSP 31178 ) . Trindade Island , Ponta da Calheta, 20°30’18.72”S / 29°18’31.67”W, depth: 15.6 m, J.B. Mendonça coll., 30.iv.2014: 5 males ( MZUSP 33422 ) , 1 male ( MZUSP 33419 ) . Ibidem , depth: 16.3 m, J.B. Mendonça coll., 20.v.2014: 1 male, 1 ovigerous female ( MZUSP 33421 ) . Ibidem , depth: 16.6 m, J.B. Mendonça coll., 08.v.2014: 1 ovigerous female ( MZUSP 33418 ) . Ibidem , depth: 16 m, J.B. Mendonça coll., 11.xi.2014: 2 males ( MZUSP 33427 ) , 2 ovigerous females ( MZUSP 33423 ) . Ibidem , depth: 16.6 m, J.B. Mendonça coll., 08.v.2014: 1 male, 1 ovigerous female ( MZUSP 33420 ) . Ibidem , depth: 17 m, J.B. Mendonça coll., 20.x.2014: 1 male ( MZUSP 33429 ) . Trindade Island , Praia do Lixo, 20°31’29.8”S / 29°19’43.9”W, depth: 13.7 m, J.B. Mendonça coll., 25.10.2014: 2 males ( MZUSP 33424 ) . Trindade Island , Enseada da Cachoeira (Farrilhões), 20°31’22.4”S / 29°19’52.0”W, depth: 11.9 m, J.B. Mendonça coll., 16.vi.2012: 1 juvenile ( MZUSP 31158 ) . Trindade Island , Enseada da Cachoeira (Farrilhões), 20°31’29.8”S / 29°19’52.0”W, depth: 17 m, J.B. Mendonça coll., 23.vii.2015: 1 male ( MZUSP 33436 ) . Martin Vaz Island , 20°30’45.7”S / 29°18’21.9”W, depth: 13 m, J.B. Mendonça coll., 23.vii.2013: 1 ovigerous female ( MZUSP 31169 ) . Size of largest male: cl 3.5 mm ( MZUSP 33419 ) ; largest female: cl 5 mm ( MZUSP 33418 ) .

Comparative material examined: Chile: Isla de Pascua (Easter Island), 15.iii.2016, leg. G. Guzmán: 2 males, 2 ovigerous females ( MZUSP 34760 ). Size of largest male: cl 4 mm; largest female: cl 7 mm .

Type locality: Cuba .

Distribution: Circumtropical. Western Atlantic: Bermuda, Gulf of Mexico, West Indies, Brazil (Rio Grande do Norte, Trindade Island – present study) ( Manning, 1963; Chace, 1972; Santos, 1994; Ramos- Porto & Coelho, 1998; Álvarez et al., 1999; Felder et al., 2009). Central Atlantic: Ascension and St. Helena Island ( Brown, 2014; De Grave et al., 2014). Eastern Atlantic: Canary Islands, Madeira, São Tomé ( Holthuis, 1949; Araújo, 2002; Wirtz, 2003, 2004). Indo-West Pacific: from east Africa and India to Japan, South China Sea, Papua New Guinea, Australia, Tuamotu and French Polynesia. East Pacific: Eastern Island ( Fransen, 1987 and this report) ( Holthuis, 1949; Fransen, 1987, 1994; Bruce, 1989; Li, 1997; De Grave, 2000; Ahyong, 2003; Prakash et al., 2015)

Ecological notes: Gnathophyllum americanum is either free-living (reefs, under stones, coral rubble, seagrass flats, seaweed-covered rocks) or loosely associated with corals (e.g., Montipora, Porites ) and echinoids (e.g., Diadema , Echinometra , Lytechinus ) in intertidal rocky pools or subtidally down to 50 meters ( Holthuis, 1949; Manning, 1963; Chace, 1972; Bruce, 1989; Fransen, 1994; Álvarez et al., 1999; De Grave, 2000; Wirtz, 2003; De Grave et al., 2014; Prakash et al., 2015).

Remarks: In Brazil, G. americanum has been recorded from Rio Grande do Norte (Extremoz, north of Natal) by Santos (1994) and most probably also occurs in Bahia (Praia de Itapoã) based on a record of “ Gnathophyllum sp.” by Coelho, & Ramos (1972:145). Gnathophyllum americanum is recorded herein from TMV, between 9.9 and 30.3 m. In Trindade G. americanum was found associated with sea anemones ( Telmatactis sp.), in the vicinity of Diadema antillarum ( Fig. 4D ) or free-living in crevices and under stones, either as single individuals or in small groups of up to four individuals, sometimes found sharing the same crevice with T. amboinensis .

Figures

FIGURE 3: A-B, Gnathophyllum americanum Guérin-Méneville, 1855. A, Ovigerous female, cl 4.5 mm, lateral view (MZUSP 33418). B, Male, cl 3.5 mm, dorsal view (MZUSP 33419). C-D, Gnathophyllum circellum Manning, 1963, male, cl 4.2 mm, lateral and dorsal views, respectively (MZUSP 33411). E, Pontonia manningi Fransen, 2000, male, cl 5.7 mm (MZUSP 35286). F, Trindade Island, Farol, Enseada dos Portugueses, 10 m. Pina sp., bivalve usually hosting P. manningi. Scales: A-B, 4.5 mm. C-D, 4 mm. E, 5.5 mm. Photographs by JBM.

FIGURE 4: A-B, Thor amboinensis (De Man, 1888). A, Ovigerous female, lateral view, cl 4 mm (MZUSP 35276). B, Male, cl 1.9 mm, dorsal view (MZUSP 33434). C, Thor manningi Chace, 1972, ovigerous female, cl 1.4 mm, lateral view (MZUSP 35277). D, Sea anemone Telmatactis sp. and sea urchin Diadema antillarum (under a stone flipped upside down) to which T. amboinensis and Tuleariocaris neglecta are usually attracted. E-F, Tuleariocaris neglecta Chace, 1969, lateral views. E, Ovigerous female, cl 3.5 mm (MZUSP 35282). F, Live male, cl 2 mm (MZUSP 33414). Note in F the shrimp holding itself to the spine of a sea urchin, head towards the base of the spine. Scales: A, 4 mm. B, 2 mm. C, 1.5 mm. E, 3.5 mm. F, 2 mm. Photographs by JBM.