Alpheopsis aequalis Coutière, 1897 sensu

Anker, Arthur, Tavares, Marcos & Mendonça, Joel B., 2016, Alpheid shrimps (Decapoda: Caridea) of the Trindade & Martin Vaz Archipelago, off Brazil, with new records, description of a new species of Synalpheus and remarks on zoogeographical patterns in the oceanic islands of the tropical southern Atlantic, Zootaxa 4138 (1), pp. 1-58 : 10-12

Alpheopsis aequalis Coutière, 1897 sensu lato

Alpheopsis aequalis Coutière 1897: 382 ; Armstrong 1941: 5 (partim?), figs. 1 D, J, W-W’’, X-X’’; Miya 1983: 17, fig. 1. Alpheopsis equalis — Coutière 1903: 89, figs. 35, 36; Banner 1953: 15, fig. 4; Banner & Banner 1973: 342, fig. 16. Alpheopsis equalis var. truncatus Coutière 1903: 89 , figs. 37, 38.

Alpheopsis consobrinus de Man 1910: 305 ; de Man 1911: 178, (1915) pl. 5, fig. 16.

[a more complete synonymy will be provided in the revision of the Alpheopsis aequalis species complex (A. Anker, in prep.)]

Material examined. Brazil: 1 male, 2 ovig. females, MZUSP 34115, Trindade Island, Enseada dos Portugueses, Farol, 20°29’52.3”S – 29°19’15.6”W, depth: 12.6 m, ARS, coll. J.B. Mendonça, 06.vii.2015; 1 male, 1 female, OUMNH.ZC. 2016.02.0 0 1, same collection data; 1 male, MZUSP 31000, Trindade Island, Enseada dos Portugueses, Farol, 20°29’52.3”S – 29°19’15.6”W, depth: 13.2 m, coll. J.B. Mendonça, 10.vii.2012; 1 ovig. female, MNHN-IU-2014-12826, Trindade Island, Enseada dos Portugueses, Ponta da Calheta, 20°30’18.7”S – 29°18’31.6”W, depth: 13.9 m, ARS, coll. J.B. Mendonça, 05.xi.2014; 1 ovig. female (missing chelipeds, tentative identification), MZUSP 31882, TAAF MD 55 / Brésil 1987 campaign, sta. 17 / DC30, Espírito Santo, off Vila Velha, Vitória-Trindade Seamount Chain, 20°26’72”S – 36°17’30”W, depth: 60 m, rocks with calcareous algae and some sand, 15.x.1987. Size of largest male: cl 2.7 mm, largest female: cl 2.7 mm ( MZUSP 34115).

Additional (extra-limital) material examined. Honduras: 1 ovig. female, OUMNH.ZC. 2007.20.0 0 91, Caribbean coast, Utila Island, West of Ragged Cay, 16º05.294’N – 86º59.844’W, depth: 20 m, coral rubble, coll. A. Anker & S. De Grave, 04.vii.2007 (fcn H134). Panama: 1 male, 2 ovig. females, MZUSP 34218, Pacific coast, Coiba Archipelago, Coibita Island, rocky intertidal, under rocks and rubble at low tide, coll. A. Anker et al., 20.iii.2007 (fcn 07-105, 07-106, 07-107); 2 males, 2 ovig. females, OUMNH.ZC. 2016.02.0 0 3, Pacific coast, Coiba Archipelago, Isla Coibita, rocky intertidal, under rocks and rubble at low tide, coll. A. Anker, 22.iii.2007 (fcn 07-158, 07-161, 07-162, 07-179); 1 male, MNHN-IU-2014-12831, Pacific coast, Coiba Archipelago, Isla Uva, “Sediment Bay”, coll. I.S. Wehrtmann, 14.iii.2006.

Comparative material examined. Alpheopsis labis Chace, 1972 . Antigua & Barbuda: holotype, female, USNM 135355, Antigua Island, Charlotte Point, English Harbour, Smithsonian-Bredin Expedition sta. 73-56, 02.iv.1956. French Antilles: 1 ovig. female, OUMNH.ZC. 2016.02.0 0 2, Saint Martin, Chicot Island, coral rocks, coll. A. Anker, 23.iv.2012 (fcn 12-017). Honduras: 1 male, OUMNH.ZC. 2007.20.0 0 81, Utila, Diamond Cay, 16°03.851’N – 86°57.507’W, depth: 10 m, coral reef, under coral rubble, coll. A. Anker & S. De Grave, 06.vii.2007 (fcn H213). Belize: 2 ovig. females, MZUSP 34213, Carrie Bow Cay, depth: 3–20 m, in sponges Lissodendoryx spp., Mycale spp., Xestospongia spp., coll. E. Tóth, 15.iii.2006. Panama: 1 ovig. female, OUMNH.ZC. 2016.02.0 0 4, Isla Grande, depth: <1 m, under rocks on silty sand, coll. A. Anker, 21.iv.2006 (fcn 06-396); 1 ovig. female, MZUSP 34216, Isla Grande, western point, depth: <1 m, under coral rubble, coll. A. Anker, 04.ix.2006 (fcn 06-462); 1 ovig. female, MZUSP 34217, Isla Grande, northern shore, shallow bay with coral rubble, depth: <1 m, under coral rubble, coll. A. Anker, 05.ix.2006 (fcn 06-450); 1 male, OUMNH.ZC. 2016.02.0 0 5, Bocas del Toro, Isla Solarte, depth: 0.5 m, under rocks and coral rubble near mangrove, coll. A. Anker, 30.v.2005 (fcn 05-107); 1 ovig. female, OUMNH.ZC. 2016.02.0 0 6, Bocas del Toro, Isla Bastimentos, Cayo Coral, depth: 0.5 m, under rocks and coral rubble near mangrove, coll. A. Anker, 31.iii.2008 (fcn 08-008); 1 ovig. female, MZUSP 34215, Bocas del Toro, Isla Bastimentos, Cayo Eduardo near Cayo Coral, depth: 1 m, sand flat with coral rubble, seagrass and corals, under rubble, coll. A. Anker, 31.iii.2008 (fcn 08-016); 1 male, OUMNH.ZC. 2016.02.0 0 7, Bocas del Toro, Isla Colón, Punta Caracol, depth: 1–2 m, under coral rubble, coll. A. Anker, 30.iii.2008 (fcn 08-001). USA: 1 ovig. female, FLMNH UF 31607, Florida, western coast, north-northwest of St. Petersburg, south of Big Bend, 28.4383° -84.2725°, depth: 33.5 m, hard bottom sponge reef, coll. J. Slapcinsky, 23.v.2012 (fcn BFLA-2366). Brazil: 1 male (damaged: broken into two halves), 1 ovig. female, MZUSP 25334, REVIZEE — Comissão Central 2 campaign, Astro Garoupa sta. 9c, southern Bahia, continental shelf margin off Caravelas, 17°41’13” S – 37°41’54” W, depth: 70 m, 27.x.1997.

Alpheopsis allanhancocki Wicksten, 1992 . Panama: 1 female, MZUSP 34220, Pacific coast, Las Perlas Archipelago, Isla Bartolomé (near Isla Contadora), rock-sand intertidal, under rocks and coral rubble and in rock crevices, coll. A. Anker et al., 31.iii.2006 (fcn 06-347); 1 ovig. female, OUMNH.ZC. 2016.02.0 0 8, Pacific coast, Las Perlas Archipelago, small island near Isla Saboga, depth: 1–2 m at low tide, under rocks and coral rubble and in rock crevices, coll. A. Anker et al., 15.ix.2005 (fcn 05-117); 1 male, OUMNH.ZC. 2016.02.0 0 9, Pacific coast, Taboga Archipelago, Isla de Taboga, rocky intertidal and partly exposed corals ( Pocillopora ), under rocks and in coral rubble, coll. A. Anker et al., 19.ii.2007 (fcn 07-039); 1 ovig. female (missing both chelipeds, tentative identification), MZUSP 34219, Pacific coast, Coiba Archipelago, Coibita Island, rocky intertidal, under rocks and rubble at low tide, coll. A. Anker, 22.iii.2007 (fcn 07-157). Colombia: 1 male, OUMNH.ZC. 2016.02.0 37, Pacific coast, Bahía Málaga, Los Negros, 03°59’22.7”N- 77°17’46.6”W, sand-rock bottom, depth: 2 m, ARS, coll. J.F. Lazarus-Agudelo et al., 25.iv.2009 (fcn COL-00112); 1 female, OUMNH.ZC. 2016.02.0 38, Pacific coast, Bahía álaga, Curichichi, 03°59’38.8”N- 77°18’45.1”W, mud-silt bottom with rocks, depth: 6.5–7 m, ARS, coll. J.F. Lazarus-Agudelo et al., 26.iv.2009 (fcn COL-00186).

Alpheopsis cf. consobrinus de Man, 1910 . Papua New Guinea: 1 ovig. female, MNHN-IU-2014-6063, Madang lagoon, sta. PM41, 05°08’07.44”S – 145°49’16.45”E, coll. P. Lozouet et al., 27.xi.2012 (fcn PM41-PZD-620C); 1 male, MNHN-IU-2014-6069, Madang lagoon, sta. PR202, 05°10’19.47”S – 145°50’18.49”E, depth: 2–4 m, coll. J. Arbasto & N. Saguil, 07.xii.2012 (fcn PR202-PZD-599A). Philippines: 1 female, 1 ovig. female, MNHN-IU-2014- 12832, Panglao Island, Doljo Point, sta. B12, 09°35.6’N – 123°43.2’E, depth: 24–27 m, reef slope, coll. MNHN and Panglao Marine Biodiversity Project team, 14.vi.2004. French Polynesia: 1 ovig. female, OUMNH.ZC. 2016.02.0 10, Society Islands, Moorea lagoon, in living coral colony ( Pocillopora sp.), coll. M. Leray, viii.2010 (fcn 1808-B7-2F1-003); 1 male, OUMNH.ZC. 2016.02.0 11, Society Islands, Moorea, Temae, close to public beach, under dead corals and rubble, coll. A. Anker, 07.xi.2009.

Description. See Coutière (1897) for brief original description and Banner & Banner (1973) for description and illustrations.

Distribution. Almost pantropical (absent from the eastern Atlantic), possible species complex (see below). Western Atlantic: Honduras: Utila; Brazil: Vitória-Trindade Seamount Chain and Trindade Island (present study). Eastern Pacific: Panama (present study). Indo-West Pacific: Red Sea to Japan, Australia and Hawaii ( Banner & Banner 1973; Chace 1988).

Ecology. Coral reefs and other hard or mixed bottom habitats rich in rocks, crevices, coral rubble, coralline algae etc.; under rocks and coral rubble, in crevices of dead coral heads, rubble, clumps of coralline algae etc.; intertidal and shallow subtidal to at least 60 m.

Remarks. Alpheopsis aequalis is a problematic taxon that needs a thorough taxonomic revision. Coutière’s (1897) original description of A. aequalis based on material from the “Red Sea and Indian Ocean” is extremely superficial and without illustrations. Later, however, Coutière provided some details on ecology and colouration of the species, as well as some drawings ( Coutière 1899, 1903). He also established a variety, A. equalis var. truncatus Coutière 1903 (hereafter A. aequalis truncata as the gender of Alpheopsis is feminine, see Anker et al. 2005), separating it from the nominal variety by the shorter, “truncate” rostrum, the presence of a subacute tooth on the pterygostomial angle of the carapace, a longer stylocerite and unequal chelipeds (cf. Coutière 1903: figs. 35–38). Based on the rich material collected by the Siboga Expedition, de Man (1910, 1911) described and provided some illustrations of A. consobrinus de Man, 1910 , from eastern Indonesia. He separated A. consobrinus from A. aequalis by the presence of a small pterygostomial tooth and from A. aequalis truncata by the slender, non-truncate rostrum. Importantly, based on the field colour notes of Coutière (1899) in Djibouti, A. aequalis is uniformly orange, whereas most specimens assignable to either A. consobrinus or A. aequalis truncata have bright-red transverse bands on the carapace and pleon (A. Anker, pers. obs.).

Armstrong (1941) reported and illustrated a rather remarkable variation in the shape of the pterygostomial angle of the carapace, as well as in the third, fourth and fifth pleura of specimens that he identified as A. aequalis , from several Indo-West Pacific and Caribbean localities. This author concluded that the presence of a pterygostomial tooth is an extremely variable feature and therefore placed A. consobrinus in the synonymy of A. aequalis . Similarly, Banner (1953), after having discussed the variation of the rostral shape and length, treated A. aequalis truncata as a junior synonym of A. aequalis . Both A. consobrinus and A. aequalis truncata were listed as junior synonyms of A. aequalis in Banner & Banner (1973) and Miya (1983). Noteworthy, Miya’s (1983) description of a Japanese female specimen identified as A. aequalis seems to perfectly match Coutière’s A. aequalis truncata .

Chace (1972) described Alpheopsis labis Chace, 1972 , based on a single female specimen from Antigua, and tentatively assigned Armstrong’s (1941) Caribbean specimens to that species. It was subsequently reported from several localities in the Gulf of Mexico, Caribbean Sea, Florida and Bermuda ( Pequegnat & Ray 1974; Martínez- Iglesias 1986; Abele & Kim 1986; Sterrer 1986), and also from northeastern Brazil, based on scarce offshore material from Ceará and Fernando de Noronha ( Coelho Filho 2006). Alpheopsis labis was characterised by Chace (1972) as having a rounded pterygostomial angle (cf. Chace 1972: fig. 15a), unequal chelipeds and posteriorly rounded third to fifth pleura. However, examination of the holotype of A. labis (USNM 135355) indicates that both pterygostomial angles of the carapace in this specimen bear a small acute tooth (A. Anker, pers. obs.), which leaves no doubt that Chace (1972) simply overlooked it. All present specimens referred to A. labis (see comparative material) also have this tooth. Similarly, according to Wicksten’s (1992) description and illustrations, A. allanhancocki Wicksten, 1992 has a rounded pterygostomial angle, which contradicts our observations in several specimens from Panama (see comparative material), in which this tooth is present.

The material from Trindade Island and Vitória-Trindade Seamount Chain was initially identified as “ A. cf. labis ” based on the rounded pterygostomial angle (with a small tooth in A. labis , contrary to Chace 1972, see above). In addition, the chelipeds of the complete specimens from Trindade Island differ from those of A. labis in being enlarged and equal in both sexes (vs. usually unequal and much smaller in females of A. labis ), bearing a row of conspicuous slender spiniform setae on the ventromesial margin of the merus (absent in A. labis , but present in many Indo-West Pacific specimens here referred to A. cf. consobrinus ), and with the chelae having a much wider pollex and cutting edges of both fingers armed with very small teeth (vs. larger teeth in A. labis ). All of the above features are also present in the specimens from the Caribbean coast of Honduras and Pacific coast of Panama (see extra-limital material above), which generally are morphologically nearly identical with the specimens from Trindade Island. Remarkably, the bright orange colouration of these specimens perfectly matches that of A. aequalis , as described by Coutière (1899). In contrast, all specimens of A. labis and A. allanhancocki (see comparative material examined) display red transverse bands, similar to those of the Indo-West Pacific individuals (A. Anker, pers. obs.). Unfortunately, the colouration of the Trindade Island specimens was not recorded.

In summary, striking differences in colouration (orange vs. red-banded), corroborated by some discrepancies in morphology, strongly suggest (1) the presence of at least two species of the A. aequalis species complex in the western Atlantic, one of them being A. labis and the other either closely related to or identical with A. aequalis ; (2) the presence of at least two species of the A. aequalis species complex in the eastern Pacific, one of them being A. allanhancocki and the other either closely related to or identical with A. aequalis ; and (3) the presence of two or three species of the A. aequalis species complex in the Indo-West Pacific, one of them being A. aequalis sensu stricto and the other corresponding to A. aequalis truncata and (if not the same) A. consobrinus . Since the material from Trindade Island appears to be morphologically closer to A. aequalis than to A. labis , it is preliminarily treated under Alpheopsis aequalis sensu lato, awaiting an exhaustive revision of the entire A. aequalis species complex, a study that would certainly require DNA sequencing (A. Anker, pers. obs.). As a consequence, all records of A. labis after Chace (1972), including some from Brasil ( Coelho Filho 2006), will require confirmation.