Anoplodactylus prominens, Bamber, Roger & Takahashi, Yoshie, 2005

Bamber, Roger & Takahashi, Yoshie, 2005, Some littoral sea spiders (Arthropoda: Pycnogonida) from Ecuador, with a new species of Anoplodactylus Wilson, 1878 (Phoxichilidiidae), Zootaxa 815, pp. 1-8 : 4-6

Anoplodactylus prominens sp. nov.

Figure 1 .

Material: 1 male, holotype ( BMNH 2004.2889), 5 males, 3 females, 1 juvenile, paratypes ( BMNH 2004.2890–98), Playas, Guayas Province, Ecuador, 02º38.23’S 80º23.3’W, 29 July 2001, low water.

Other specimens have been taken from Salinas, 02º11.67’S 80º58.85’W, Data, 02º41.42’S 80º20.17’W, and Cenaim, 01º57.62’S 80º43.72’W, all in Guayas Province, and Cojimies, Manabi Province (Lat.­Long. unavailable) (Luis Dominguez, pers. comm.).

Description of male: Trunk ( Fig.1 A, B) relatively compact, constricted without sutures. Lateral processes less than 1.5 times as long as maximum diameters, separated by less than a half of their diameters, narrowest gap between 3rd and 4th. Lateral process tubercles present dorsodistally, prominent, as tall as wide, without spine at tip. One to four tiny tubercles each with seta at tip present dorsodistally on each lateral process. Neck rather short, distolaterally with spinule on tubercle. Shoulder­like swelling present between base of neck and 1st lateral process. Ocular tubercle leaning forward, conical with pointed tip and circular base, not taller than basal width. Four pigmented eyes. Proboscis thick, moderately short, slightly curved upward at the base, with blunt tip.

Abdomen short, about 1.5 times as long as wide, held at 45 degrees to plane of trunk, distally with four short spinules each on small tubercle.

Chelifore short, slightly curved downward; scape length less than five times its diameter, bearing two dorsal small setae, and three or four dorsodistal setae, each on tubercle. Chela fingers ( Fig. 1 C) curved, stout, without teeth, slightly longer than palm, crossing at tips; movable finger slightly longer, with several setae as figured; fixed finger with few setae at the base.

Ovigers ( Fig. 1 D) of six articles; article three ( O 3) curved, with sparse dorsal and ventral setae, proximally with slight constrictions, almost twice length of O 2; O 2 and O 4 with sparse setae; O 4 longer than O 5 and O 6 combined, two terminal articles with many setae as figured, all setae of O 6 curved.

Legs ( Fig. 1 E, F) relatively compact and setose, with many small strong protuberances each bearing short seta, single longer dorsodistal seta on femur and each tibia, slightly shorter than half diameter of each article. Second coxa almost twice length of first or third coxa; femur almost equal in length to second tibia, 1.5 times as wide as second tibia; first tibia 0.8 times as long as femur. Cement gland opening on femur mid­dorsal, tube­shaped, about one­third as long as femur diameter. Tarsus very short, with few setae and one spine ventrally, with one seta dorsally. Propodus with heel at right angles to sole, laterally with a few short setae, dorsally with many setae and small tubercles. Heel with two larger heel spines and two slender spines. Sole with five to eight spines and short lamina spanning 0.25 times length of sole, flanked by short setae. Main claw wide, 0.6 times length of propodus, curved gently; auxiliary claws almost 0.15 times length of main claw. Prominent ventral genital spur on second coxa of fourth leg.

Female without oviger or cement gland tube; genital pores present on a ventral eminence on coxa 2 of all legs.

Measurements (holotype, in mm): trunk length (chelifore insertion to tip of 4th lateral process), 0.76; trunk width (across 2nd lateral processes), 0.59; proboscis ventral length, 0.43; third leg, coxa 1, 0.14; coxa 2, 0.33; coxa 3, 0.21; femur, 0.55; tibia 1, 0.44; tibia 2, 0.53; tarsus, 0.08; propodus, 0.33; claw, 0.21; auxiliary claw, 0.02

Etymology: This new species is named for the prominence of the lateral process tubercles and the setose protuberances on the legs and chelifore scape (Latin: prominens — a prominence in anatomy).

Remarks: Anoplodactylus prominens sp. nov. resembles Anoplodactylus maritimus Hodgson, 1915 and A. petiolatus (Krøyer, 1844) in size of lamina, cement gland configuration, and shape of the oviger. Anoplodactylus maritimus has been confused with A. petiolatus in the past ( Stock, 1975a; Child, 1992b) because of their similarity. Although these species share characters in common, there are clear distinctions between the three. The present species resembles A. maritimus in having the shoulder­like swelling at the base of neck and the narrow gap between lateral processes. However, the present species is distinguished from A. maritimus by having the lateral process tubercles and the distal setae on tiny tubercles on the lateral processes, on the leg articles, and chelifore scape, as well as having a longer chelifore scape. Compared with A. petiolatus , A. prominens has a much more compact body, shorter and stouter leg articles and abdomen, and a shorter ocular tubercle which does not overhang the proboscis; the lateral processes are less separated, and the setae on the legs shorter. The Caribbean species A. allotrius Child, 1979 shows similarities to A. prominens in its propodal ornamentation, the cement­gland­tube configuration, the spinules on the anterior­lateral margin of cephalon and lateral process tubercles; however, unlike the present species, A. allotrius has some trunk segmentation, a cephalon overhanging the proboscis more (although less than A. petiolatus ), and characteristic denticulation of the moveable finger of the chela.

Figures

FIGURE 1. Anoplodactylus prominens sp. nov., holotype, A, body, dorsal; B, body, lateral; C, chela; D, oviger; E, third leg; F, distal articles of third leg. Scale lines = 0.5 mm for A, B and D, 0.1 mm for C, 0.67 mm for E, 0.25 mm for F.