Anoplodactylus eroticus Stock, 1968

Lucena, Rudá Amorim, Araújo, Joafrâncio Pereira De & Christoffersen, Martin Lindsey, 2015, A new species of Anoplodactylus (Pycnogonida: Phoxichilidiidae) from Brazil, with a case of gynandromorphism in Anoplodactylus eroticus Stock, 1968, Zootaxa 4000 (4), pp. 428-444 : 435-440

Anoplodactylus eroticus Stock, 1968

( Figs 12 –28)

Material examined: Alagoas: ( UFPB.PYC–131) 1♂, Pontal do Coruripe, 26 Jan 1983, coll. M.L. Christoffersen & P. Young. Paraíba: ( UFPB.PYC–017) 3♂, 7♀, Barra de Mamanguape, 11 Aug 2010, coll. PBP; ( UFPB.PYC– 061) 3♂, Coqueirinho, 28 Aug 2011, coll. PBP; ( UFPB.PYC–064) 1♂, Coqueirinho, 0 3 Jun 2008, coll. Projeto Biota, intertidal; ( UFPB.PYC–102) 7♂, 5♀, Coqueirinho, 0 6 Nov 2013, coll. R.A. Lucena, on hydroids; ( UFPB.PYC–122) 1♀, Tabatinga, 0 1 Sep 2011, coll. PBP; ( UFPB.PYC–166) 2 gynandromorphs, Barra de Mamanguape, 11 Aug 2010, coll. PBP. Rio Grande do Norte: ( UFPB.PYC–101) 1♂, Ponta do Mel, 23 Jun 1982, coll. A.I Kanagawa, on algae. Ceará: ( UFPB.PYC–120) 1♂, 2♀, Ponta Grossa, 24 Jun 1982, coll. A.I. Kanagawa. Maranhão: ( UFPB.PYC–121) 2♂, 1 juv, Praia do Olho de Porco, São Luís, 31 Jul 1982, coll. A.I. Kanagawa.

Description of male (UFPB.PYC–017): Trunk elongated and fully segmented. Proboscis elongated and cylindrical, but with a slight submedian constriction. Lateral process separated by less than half of their diameter; with two to three dorsal long setae. Ocular tubercle conical and pointed, higher than abdomen, with a seta on each side; large and dark eyes. Abdomen erect, conical, with two subapical setae (figs 12 and 13).

Cheliphore slender, reaching tip of proboscis. Scape single-jointed, with sparse setae; two to three elongated setae near the terminal margin. Chelae with three dorso-distal setae. Movable finger with a row of setae on the outer margin; immovable finger with three dorsal setae (fig 14), unthoothed.

Oviger 6-jointed (fig 15). 1st article two times as long as large, without seta. 2nd article half the length of 3rd. 3rd longest article, curved in a slight S-curvature, with a row of setae in each lateral margin. 4th article longer than 5th, with a row of six setae in the outer margin. 5th article with several setae. 6th article very small and with several setae. Oviger with several small pores that open along its entire extension.

FIGURES 25–28. Anoplodactylus eroticus (UFPB.PYC–017; UFPB.PYC–166). 25, 4th leg of gynandromorph A.; 26, leg of male; 27, 4th leg of female; 28, 4th leg of gynandromorph B. Scale bar: Figs. 25–28, 0.25mm. CG: Cement gland; In: Intestinal diverticulum; Ov: Ovarium.

Elongated legs, with several setae and small pores in cuticle (fig 16). Coxae 1 and 3 of same size. Coxa 1 with two elongated setae in each lateral surface. Coxa 2 longer than coxae 1 and 3 together; genital spur elongated in all legs, with an apical genital pore in legs 3 and 4. Coxa 3 with a ventral seta. Femur is the longest article, with a row of setae on the distal margin, and a terminal tubercle, having an apical seta. Cement gland before half length of femur; tube oval-shaped and small, forming an acute distal angle (detail of fig 16). Tibia 1 and 2 of same size, but the first is more robust. Tarsus short, with several ventral setae. Propodus with well developed heel (fig 17); heel with three spines on apex, and three elongated spines on the inner margin, turned towards sole; sole with nine short spines, forming a kind of cutting lamella (detail in fig 17). Main claw 2/3 length of propodus, with seven to nine small lateral tubercles. Auxiliary claws reduced.

Measurements (Male—mm): length of trunk, 1.88; width of trunk (measured in first lateral processes), 1.05; length of abdomen, 0.23; length of proboscis, 1.11; length of scape of cheliphore, 0.96; length of chela, 0.39; length of articles of 3rd leg—coxa 1, 0.38; coxa 2, 0.85; coxa 3. 0.41; femur, 1.57; tibia 1, 1.26; tibia 2, 1.39; tarsus, 0.16; propodus, 0.72; main claw, 0.55; auxiliary claw, 0.0 7.

Female: Female with less and smaller setae than male (figs 18 and 20). Lateral processes, legs and cheliphores with short setae. Ocular tubercle more pointed than in males. Spur less robust than in male. Genital spur opening subapically in all legs. Propodus with 10 spines on sole. All female have four rounded tubercles on the ventral surface at the proximal region of proboscis, two proximal tubercles larger than the two distal ones (fig 19).

Depth: Not cited.

Distribution: India; USA (Hawaii).

Comments: Stock (1968a) described A. eroticus based on only two male specimens. The main diagnostic characters are: legs with long ventral genital spurs on coxa 2, small spines on lateral processes and tube of cement gland small and distally erect. The female of A. eroticus was described by Arango & Maxmen (2006) on the basis of specimens from Hawaii. They are very similar to males, differing sexually in having two pairs of ventral rounded protuberances at the basis of the proboscis, the proximal pair being directed forwards and being slightly bigger than the distal pair (figs 19 and 23). Differences were observed by us in the position of the genital pores. In males the genital pore occurs at the apex of the spur, while in females it occurs in the subapical portion.

We observed few differences in relation to these descriptions: in the number of setae on the appendages, which are more numerous than in the description of Stock (1968a); and in the number of spines in the sole of the propodus, which varied from nine to ten. Regarding females, our material presented three short setae on the lateral processes (smaller than in males), while in Arango & Maxmen (2006) the lateral processes are smooth, apparently lacking ornamentation entirely. We consider these differences as representing morphological variations.

We also detected small variations in the material examined. While specimens from the State of Paraíba were yellowish after fixation, those from the State of Ceará presented a more opaque coloration (beige) and a smaller size. The material from the State of Maranhão was slightly darker, brownish in color. In one male and one juvenile we observed a superficial segmentation between trunk segments 3 and 4, while in the gynandromorph such a division is not present. In all remaining male and female specimens the division between segments 3 and 4 is quite conspicuous.

A. eroticus was recorded for India and Hawaii, and in 2006 for Hawaii for the second time. We provide the first record for the Atlantic. Despite the present disjunct distribution, no significant morphological differences were found for the new material, which leads us to classify our specimens as belonging to the same species as the Indo- Pacific material.

Carlton & Eldredge (2009) classified A. eroticus as a species introduced into Hawaii, being found in the Port of Honolulu. In this same region (Port Kewalo, Honolulu), Arango & Maxmen (2006) recorded specimens associated with the hydroid Pennaria disticha Goldfuss, 1820 , which grows attached to suspended objects such as anchorage cords and ship hulks. This hydroid is widely distributed in tropical and warm-temperate regions of the globe, being possibly native to the western Atlantic ( Knapp et al. 2011), from where it has been dispersed to other port regions ( Carlton & Eldredge, 2009; Knapp et al. 2011). Although P. disticha is widely distributed in Brazil ( Grohmann et al. 2011), none of our specimens of A. eroticus were found associated with Pennaria disticha , nor were collected in port areas. We believe that A. eroticus may be subject to accidental transportation, such as observed for P. disticha , which would account for its present broad distribution pattern.

Figures

FIGURES 12 – 17. Anoplodactylus eroticus (UFPB. PYC – 017). Male. Habitus: 12, dorsal; 13, lateral; 14, chela; 15, oviger; 16, 3 rd leg 17, propodus. Scale bar: Figs. 12 – 13, 1 mm; Fig. 14, 0.125 mm; Fig. 15, 0.1 mm; Fig. 16, 0.25 mm, detail, 0.05 mm; Fig. 17, 0.05 mm, detail, 0.025 mm.