Thor manningi Chace, 1972

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 : 162-163

Thor manningi Chace, 1972

( Figure 4C )

Material examined: Brazil: Trindade Island , Ponta Norte, 20°29’18.7”S / 29°20’18.3”W, depth: 11.3 m, J.B. Mendonça coll., 23.vi.2016: 1 ovigerous female ( MZUSP 35277 ) . Trindade Island , Enseada dos Portugueses (Farol), 20°29’52.3”S / 29°19’15.6”W, depth: 14.6 m, J.B. Mendonça coll., 10.vii.2012: 7 males, 1 ovigerous female ( MZUSP 31151 ) . Trindade Is- land, 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 31202 ) . Trindade Island , Praia da Calheta, 20°30’20.9”S / 29°18’43.7”W, depth: 11.6 m, J.B. Mendonça coll., 18.vii.2012: 2 ovigerous females ( MZUSP 31192 ) . Trindade Island , Ilha da Racha, 20°30’26.5”S / 29°20’48.0”W, depth: 27.1 m, J.B. Mendonça coll., 22.vi.2012: 1 male ( MZUSP 31152 ) . Trindade Island , Enseada da Cachoeira (Farrilhões), 20°31’22.4”S / 29°19’52.0”W, depth: 17.9 m, J.B. Mendonça coll., 04.vii.2010: 1 male ( MZUSP 31161 ) . Trindade Island , Farrilhões (Enseada da Cachoeira), 20°31’22.4”S / 29°19’52.0”W, depth: 9.5 m, J.B. Mendonça coll, 08.vii.2013: 2 males ( MZUSP 31186 ) . Size of largest male: cl 1.9 mm ( MZUSP 33434 ) ; largest female: cl 1.4 mm ( MZUSP 35277 ) .

Comparative material examined: Panama: Bocas del Toro, A. Anker et al., coll., viii.2008: 1 ovigerous female, cl. 3 mm ( MZUSP 33084 ) . Brazil: Banco de Abrolhos, REVIZEE, Comissão Central , Stn VV 33, 18°53’26”S /39°13’87”W, depth: 37 m, M. Tavares coll., 28.ii.1996: 1 ovigerous female, cl 2 mm ( MZUSP 32048 ) .

Type locality: English Harbour , Antigua .

Distribution: Western Atlantic: Bermuda, North Carolina to Brazil (Seamounts of the North Brazilian Chain, Fernando de Noronha, Ceará to São Paulo, Trindade Island – present study). Central Atlantic: Ascension Island ( Chace, 1972; Manning & Chace, 1990; Williams, 1984; Christoffersen, 1998; Coelho Filho, 2006; Almeida et al., 2012; De Grave et al., 2014). The record of T. manningi from the eastern Pacific Ocean (Islas Tres Marías, Mexico) actually refers to T. algicola Wicksten, 1987 ( Chace, 1972; Wicksten, 1987).

Ecological notes: Free-living in seagrass flats, dead corals, clumps of coralline algae, in submerged wood or in association with macroalgae, hydroids, corals ( Millepora ) and occasionally with sea anemones ( Bartholomea ). Lindberg & Stanton (1988) observed T. manningi cleaning the brachyuran crab Pilumnus sayi ; the two species were also associated in the field. From the tide line down to 44 m ( Chace, 1972; Williams, 1984; Almeida et al., 2012).

Remarks: Thor manningi is a common western Atlantic species also known from the central Atlantic ( Ascension Island) and is herein recorded for the first time from Trindade.

Family Palaemonidae Rafinesque, 1815 Gnathophylloides mineri Schmitt, 1933

Material examined: Brazil: 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 juvenile ( MZUSP 31154 ) . Ibidem , depth: 13.2 m, J.B. Mendonça coll., 08.v.2014: 1 juvenile ( MZUSP 33398 ) , 1 male ( MZUSP 35278 ) . Ibidem , depth: 15.4 m, J.B. Mendonça coll, 08.vii.2015: 1 male ( MZUSP 33435 ) . Trindade Island , Ponta da Calheta, 20°30’37.6”S / 29°18’28.1”W, depth: 2-4 m, J.B. Mendonça coll., 13.vi.2012: 1 ovigerous female ( MZUSP 31157 ) . Trindade Island , Ponta da Calheta, 20°30’18.72”S / 29°18’31.6”W, depth: 17.7 m, J.B. Mendonça coll, 03.viii.2015: 1 male ( MZUSP 33437 ) . Size of largest male: cl 2.1 mm ( MZUSP 35278 ) ; largest female: cl 2.2 mm ( MZUSP 31157 ) .

Comparative material examined: Trinidad and Tobago: Tobago, Man O War Bay , House Reef, from Lytechinus variegatus , 11°19.221’N / 60°33.100’W, depth: 5 m, S. De Grave coll., 18.ix.2003: 2 ovigerous females, largest cl 3 mm ( MZUSP 31031 ) . Brazil: Guarapari , Ilha Escalvada, from Tripneustes ventricosus , depth: 10 m, P. Wirtz coll., vi.2006: 2 males?, largest cl 1.8 mm, 7 ovigerous females, largest 2.2 mm ( MZUSP 17007 ) .

Type locality: Ballena Point , Ensenada, Puerto Rico .

Distribution: Disjunct circumtropical. Western Atlantic: southeastern Florida, Mexico, Caribbean coast of Colombia, Puerto Rico, Tobago and Brazil (Bahia, Espírito Santo and the oceanic island of Trindade – present study). Indo-West Pacific: Zanzibar, Seychelles, Australia (North Solitary Island, New South Wales), Hawaii. Eastern Pacific: Malpelo off Colombia ( Castro, 1971; Bruce, 1974, 1988; Abele, 1975; Alves et al., 1995; Ramos-Porto & Coelho, 1998; Álvarez et al., 1999; Felder et al., 2009; Wirtz et al., 2009; Campos et al., 2010).

Ecological notes: Gnathophylloides mineri is a small species, free-living (under stones, coral rocks, awash waterlogged teredo-ridden stumps, see Chace, 1972) or, most commonly, in association with sea urchins (e.g., Heliocidaris , Heterocentrotus , Lytechinus , Pseudoboletia , Tripneustes ) on which it is found generally in groups amongst the spines usually near the oral surface. The shrimp has a number of behavioral, morphological and color adaptations, which renders it difficult to be detected on the urchin: arrange itself longitudinally along the urchin spine, head towards the apices of the spine; claw of second pereopod held parallel to the urchin spine and similar in diameter to the spine; short antennules and antennae held back over the body so that they do not overreach the urchin spine; pereopods dactyli short, furnished with a grasping projection ventrally that seems of help to hold the urchin spine; cryptic coloration to be well camouflaged against the test and spines of the urchin (particularly when associated with Tripneustes ). Gnathophylloides mineri feeds on the epithelium covering the sea urchin spines, although filter feeding has also been reported ( Patton et al., 1985). The shrimps can detect its host, e.g., Tripneustes gratilla , from a distance using visual and chemical cues ( Lewis, 1956; Castro, 1971; Criales, 1984; Patton et al., 1985; Okuno & Tanaka, 2001; Maciá & Robinson, 2009; Williamson et al., 2012).

Remarks: Gnathophylloides mineri is disjunct circumtropical in distribution, being absent from the central and eastern Atlantic oceans. The species has been previously reported from the Brazilian shore (Bahia: Ondina and Abrolhos, Espírito Santo) in association with the sea urchin Tripineustes ventricosus ( Alves et al., 1995; Wirtz et al., 2009), which was found to be the host of the Trindade specimens.

Figures

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.