Anoplodactylus ricardoi, Lucena & Christoffersen, 2018

Lucena, Rudá Amorim & Christoffersen, Martin Lindsey, 2018, Anoplodactylus (Pycnogonida: Phoxichilidiidae) from Brazil, new records and two new species, Turkish Journal of Zoology 42 (4), pp. 372-388 : 381-383

Anoplodactylus ricardoi sp. nov. ( Figures 3 a−3h)

Material examined: Rio Grande do Norte: Holotype – ( UFPB.PYC–245) 1 ♂, Praia de Pipa, intertidal, 14 Jul 2014, coll. R.A. Lucena and L.M. Falkenberg . Paratypes – ( UFPB.PYC–134) 2 ♂♂ and 1 ♀, same collection data as holotype .

Diagnosis: Segmentation incomplete, absent between segments 3 and 4. Lateral processes separated by half of diameter; elongate and with many small setae on dorsal surface. Fingers elongate, with setae at base of fixed finger; movable finger with setae in median region. Palp reduced, formed by a single cylindrical article in female. Propodus with eight spines on heel, 2 large at apex and 6 directed towards sole. Sole with eight small spines along its extension, marginalized by small setae. Female with 2 alar ornamentations, formed by small teen of distal margin, at the base of the proboscis.

Description (Male): Trunk rounded dorsally, with incomplete segmentation, absent between segments 3 and 4 ( Figures 3 a−3b). Proboscis cylindrical. Lateral processes separated by half diameter, elongate and with many small setae on dorsal surface ( Figure 3d ). Ocular tubercle conical, short; eyes well developed, strongly pigmented. Abdomen cylindrical, slightly larger than ocular tubercle, curved backwards, with distal setae.

Cheliphores with scapus uniarticulate, with sparse setae, more concentrated on distal margin. Palm of chela smaller than fingers, with many setae ( Figure 3e ). Fingers elongate, with setae at base of fixed finger; movable finger with setae in median region. Oviger with 6 articles ( Figure 3f ). First article very dilated, without setae. Setae beginning on second article. Second and third articles almost of the same size, the third being slightly bigger. Fourth and fifth articles dilated. Sixth article ovalate. Fifth and sixth articles with many setae.

Legs elongate with many setae ( Figure 3g ). Coxa 1 smaller than 3, together both smaller than coxa 2. Femur and tibia robust, with an elongate setae on dorso-distal region. Tube of cement gland short, directed upwards, forming an almost square rectangle with the femur. Tibia 1 smaller than tibia 2. Tibia 2 smaller than femur. Tarsum rectangular, larger than length; with many setae on ventral surface. Propodus with 8 spines on heel, 2 large ones at apex and 6 directed towards the sole ( Figure 3h ). Sole with eight small spines along its extension, marginalized by small setae. Main claw with two-thirds of length of propodus. Auxiliary claws strongly reduced.

Description (Female): Almost equal to male, differing by owning 2 alar ornamentations, formed by small teeth on distal margin, at base of proboscis. Palp reduced, formed by a single cylindrical article ( Figure 3c ).

Measurements (Holotype – in mm): Length of trunk, 1.66; width of trunk (above segment 2), 1.20; length of abdomen, 0.38; length of proboscis, 0.74; length of cheliphore, 0.97; third leg v coxa 1, 0.26; coxa 2, 0.61; coxa 3, 0.39; femur, 1.03; tibia 1, 0.81; tibia 2, 1.00; tarsum, 0.13; propodum, 0.67; main claw, 0.38; auxiliary claws, 0.05.

Distribution: Brazil (Rio Grande do Norte).

Type locality: Praia de Pipa , Rio Grande do Norte, Brazil .

Etymology: The specific epithet “ ricardoi ” is a homage to the professor Doctor Ricardo Lucena, from Federal University of Paraíba.

Depth: Mesolittoral.

Remarks: This species belongs to the group A. californicus-digitatus , proposed by Arango and Maxmen (2006). The group consists of 14 species that have one or more pairs of tubercles in the ventral region of the proboscis of the female.

Of the 14 known species, the new species is very similar to A. californicus and A. stictus , mainly due to the pair of alar processes on the proboscis of the female, the tube of the cement gland, and its body pattern. The absence of dorsal tubercles on the lateral processes, the presence of dentate alar processes on the proboscis of the female, and the large quantity of setae on the appendages and body are the main characters that distinguish the two species.

As for A. californicus , the closest species, we may distinguish it from Anoplodactylus ricardoi sp. nov. by the latter being more robust, with lateral processes closer to each other and larger in the distal margin, and with many small dorsal setae; ocular tubercle and abdomen more robust; ocular tubercle closer to the insertion of the cheliphores, which are conical and occupy all the lateral region of the neck; auxiliary claws almost imperceptible; presence of a small tubercle above the insertion of the ovigers.

Figures

Figure 3. Anoplodactylus ricardoi sp. nov. (UFPB.PYC–245). Adult male. Habitus: a, dorsal view (scale bar: 1 mm); b, lateral view (scale bar: 1 mm); d, lateral process (scale bar: 0.05 mm); e, chela (scale bar: 0.05 mm); f, oviger (scale bar: 0.1 mm); g, leg 3 (scale bar: 0.25 mm; detail of g: 0.025 mm); h, propodus (scale bar: 0.05 mm). (UFPB.PYC–134) Adult female. c, proboscis ventral view (scale bar: 1 mm).