Phascolosoma (Phascolosoma) cf. perlucens Baird, 1868

Fig. 6

Type locality of nominal species

Jamaica (Baird 1868: 90–91, pl. 10, fig. 2–2a).

Material examined

MEXICO – Guerrero • 2; La Quebrada; 16°50′44″ N, 99°54′54″ W; 21 Sep. 2001; depth 15–20 m, in Pinctada mazatlanica (Hanley, 1856); UMAR-SIPU 036 • 4; Ixtapa Island, Coral Beach; 17°40′37″ N, 101°39′20″ W; 19 Sep. 2007; in dead coral with algae; UMAR-SIPU 037 • 52; Ixtapa Island; 17°40′37″ N, 101°39′20″ W; 24 Sep. 2007; SGM leg.; in pier piles; UMAR-SIPU 038 • 8; Punta Maldonado Beach; 16°19′39″ N, 98°34′15″ W; 23 Sep. 2007; SGM leg.; in algae; UMAR-SIPU 039 • 8; Marquelia, Las Peñitas Beach; 16°33′16″ N, 98°46′21″ W; 22 Sep. 2007; SGM leg.; UMAR-SIPU 040 • 8; Manzanillo Beach; 16°50′31″ N, 99°54′38″ W; 22 Sep. 2007; in pier piles with sponge; SGM leg.; UMAR-041 • 3; Barra de Potosí; 17°32′19″ N, 101°26′36″ W; 3 Dec. 2010; SGG leg.; UMAR-SIPU 042 . – Oaxaca • 2; La Tijera Beach; 15°41′15″ N, 96°26′33″ W; 24 May 2004; RBR leg.; in rock; UMAR-SIPU 043 • 18; Estacahuite Beach; 15°40′05″ N, 96°28′53″ W; 18 Apr. 2005; SGM leg.; in rocks with carbonate; UMAR-SIPU 044 • 19; La Tijera Beach; 15°41′15″ N, 96°26′33″ W; 30 Apr. 2005; UMAR-SIPU 045 • 12; Estacahuite Beach; 15°40′05″ N, 96°28′53″ W; 10 Sep. 2005; in dead coral; UMAR-SIPU 046 • 2; La Tijera Beach; 15°41′15″ N, 96°26′33″ W; 12 Sep. 2006; depth 4 m, in dead coral; UMAR-SIPU 048 • 3; Chachacual Bay, Jicaral Beach; 15°42′39″ N, 96°12′11″ W; 10 Feb. 2007; depth 5.6 m, in Porites sp.; UMAR-SIPU 049 • 2; San Agustín Bay; 15°41′21″ N, 96°14′11″ W; 24 Feb. 2007; UMAR- SIPU 050 • 2; Chacahua; 15°58′07″ N, 97°32′09″ W; 13 Apr. 2007; in rocks; UMAR-SIPU 052 • 45; Chacahua; 15°58′07″ N, 97°32′09″ W; 14 Apr. 2007; SGM leg.; in artificial monticule; UMAR-SIPU 053 • 3; Huatulco, Conejos Bay; 15°46′44″ N, 96°03′51″ W; 5 May 2007; in algae; UMAR-SIPU 054 • 1; Zipolite, Playa del Amor; 15°39′37″ N, 96°30′38″ W; 13 Apr. 2007; UMAR-SIPU 055 • 1; Chacahua; 15°58′07″ N, 97°32′09″ W; 10 Nov. 2007, PHM and RBZ leg.; UMAR-SIPU 056 • 1; Huatulco, Santa Cruz Beach; 15°45′10″ N, 96°07′49″ W; 14 Dec. 2007; BMD and PHM leg.; depth 0.5 m, in pier piles; UMAR-SIPU 057 • 4; Panteón Beach; 15°39′50″ N, 96°29′42″ W; 16 Apr. 2008; JDG and GGG leg.; depth 3 m, in dead coral; UMAR-SIPU 058 • 1; La Montosa Island; 15°45′57″ N, 96°05′03″ W; 22 Feb. 2010; RGF and SGG leg.; depth 3.6 m, in Pocillopora damicornis (Linnaeus, 1758); UMAR-SIPU 059 • 36; Puerto Ángel Bay; 15°39′56″ N, 96°29′29″ W; 10 Jun. 2011; RBR leg.; depth 0.5 m, in pier piles; UMAR-SIPU 060 • 4; Agua Blanca Beach; 15°43′58″ N, 96°48′38″ W; 27 Apr. 2012; KLT leg.; UMAR- SIPU 061 • 9; Puerto Ángel Bay; 15°39′56″ N, 96°29′29″ W; 28 May 2014; ISM and JGV leg.; in pier piles; UMAR-SIPU 062 • 4; Puerto Ángel Bay; 15°39′56″ N, 96°29′29″ W; 8 Jun. 2014; ISM and JGV leg.; in pier piles; UMAR-SIPU 063 • 3; Chacahua, Cerro Hermoso Beach; 15°58′08″ N, 97°32′06″ W; 30 Apr. 2014; in mangrove root; UMAR-SIPU 064 • 5; Agua Blanca Beach; 15°43′58″ N, 96°48′38″ W; 30 Apr. 2014; UMAR-SIPU 065 • 8; Boquilla Beach; 15°40′58″ N, 96°27′54″ W; 22 May 2014; UMAR- SIPU 066 • 1; Huatulco, Santa Cruz Beach; 15°45′10″ N, 96°07′49″ W; 16 Dec. 2016; JGV leg.; in sand, UMAR-SIPU 067 • 3; Violín Beach; 15°44′24″ N, 96°07′38″ W; 1 Dec. 2016; JGV leg.; UMAR-SIPU 068 • 22; San Agustín Bay; 15°41′21″ N, 96°14′11″ W; 2 Dec. 2016; JGV leg.; UMAR-SIPU 069 • 1; La Montosa Island; 15°45′57″ N, 96°05′03″ W; 22 Feb. 2010; SGM leg.; depth 4.6 m, in Porites sp.; UMAR-SIPU 070 . – Chiapas • 19; Puerto Chiapas; 14°42′11″ N, 92°24′36″ W; 20 Sep. 2011; RBZ leg.; in pier piles, in rock with oyster; UMAR-SIPU 051 .

Description

Trunk 3–18 mm in length. Introvert as long as trunk (Fig. 6A), with patches of dark brown pigment in dorsal part. Reddish conical papillae on dorsal base of introvert, posterior to anus (Fig. 6E–F). Introvert bears 15 rings of hooks (Fig. 6D). Hooks with secondary tooth and basal triangle (Fig. 6C). Fourteen digitiform tentacles encircling nuchal organ (Fig. 6D). Longitudinal muscles of body wall combined into bands. Four retractor muscles. Two brown nephridia occupy 30% of trunk (Fig. 6B). Spindle muscle attached posteriorly.

Remarks

Although there are no morphological characters to support that the populations of Phascolosoma perlucens from the Caribbean and the Eastern Pacific are different species, the molecular data provides strong evidence of a differentiation between both populations (Kawauchi & Giribet 2010); therefore, we propose to consider this species as being near to the nominal species. It is possible that the specimens recorded here and other records from the Tropical Eastern Pacific (Fisher 1952; Dean 2001; Dean et al. 2010) are a new species.

Habitat

Intertidal and subtidal (20 m); as epibionts of Pinctada mazatlantica, in dead coral, between the fouling of pier piles, in macroalgae, in a sabellariid reef, in mangrove roots and in sand.

Distribution

Southern Mexican Pacific, from Ixtapa, Guerrero to Puerto Chiapas.