Eurycyde raphiaster Loman, 1912

Müller, Hans-Georg & Krapp, Franz, 2009, The pycnogonid fauna (Pycnogonida, Arthropoda) of the Tayrona National Park and adjoining areas on the Caribbean coast of Colombia 2319, Zootaxa 2319 (1), pp. 1-138 : 64-67

Eurycyde raphiaster Loman, 1912

Figs. 32–33

Eurycyde raphiaster Loman, 1912: 13 . Stock 1975: 979, (literature). Child 1979: 21. Stock 1979: 979. Child 1982: 360. Stock 1986: 401. Child 1988: 7. Stock 1990: 209. Müller 1992: 45

Material: 4.— 6 males (1ov.), 2 fem., 1 juv. ( SMF 1199 ), coral rubble, 18 m, 9.X.1985 .

9.— 1 juv. ( SMF 1200 ), coral rubble, 15 m, 1.VII.1985 . 1 male ( MNHN), same locality, 6 m, 4.VIII.1985 . 1 fem. ( ZSM), same locality, 6–7 m, 3.XII.1985 . 1 fem. ( ZSM), coral rubble; 12–15 m, 15.XII.1985 . 1 fem., 1 juv. ( SMF 1201 ), under stones, 2–3 m, 24.XII.1985 . 1 male (ov) ( ZMA 3371 ), same locality, 0.5–1 m, 29.XII.1985 . 1 male (ov.), 3 juv. ( ZFMK), under large blocks, 1–2 m, 4.II.1986 . 1 juv. ( SMF 1202 ), coral rubble, 5–6 m, 14.III.1986 .

12.— 2 males (1 ov.), 1 fem. ( SMF 1203 ), coral rubble, 16–18 m, 16.IX.1985 .

22.— 2 males (1 ov.), 3 fem., 1 juv. ( SMF 1204 ), Halimeda on reef top, lower mesolittoral, 14.IV. 1986 .

27.— 1 juv. ( SMF 1205 ), coral rubble among Thalassia , 1 m, 1.XI.1985 .

35.— 1 fem. ( SMF 1206 ), coral rubble overgrown by poriferans, 18 m, 2.IX.1985 . 1 male, 3 fem., 1 juv. ( INVEMAR), coral rubble 11–16 m, 23.IX.1985 .

42.— 2 males (1ov.), 1 fem., 4 juv. ( SMF 1207 ), coral rubble, 13 m, 28.II.1986 .

45.— 10 males (5ov.), 3 fem. ( SMF 1208 ), algae, hydroids and bryozoans on rock, 6–10 m, 25.IX.1985 .

Description of male: Dorsal trunk outline oval, all segments fully separated. Crurigers separated by 1/10 to 1/3 of their diameter. All crurigers normally bearing short conical dorso-distal tubercles, variably developed. Ocular process 2.3 times as high as its basal diameter, distally rounded and with ring of usually 7 long spines. Eyes feebly pigmented. Lateral origins of ovigers separated by 1/5 of their diameter from cruriger 1. Abdomen almost erect and rather short, distally bearing ring of 6 long spines. Distal part of proboscis attenuated, pyriform, greatest diameter in basal half, basal part two times as long as diameter.

Cheliphore scape two-articled, both articles of equal length. Basal article with robust dorso-distal spine; distal article with 6–8 dorsal and lateral spines and short distal seta; cheliphores rudimentary, bearing short distal seta. Palp 10-articled, two short basal basal articles; third article longest, 1.3 times as long as fifth; four distal articles densely beset with ventral setae. Oviger 10-articled, with robust terminal claw. Three basal articles short, fourth and fifth articles longest, subequal in length; articles 7–10 with serrated edges.

Legs: coxae 1 and 2 subequal in length; coxa 1 with characteristic pointed processes at distal and dorsolateral edge; distal process on coxa 1 of legs 1–3 longer than anterior one, with spines; processes on first coxa of leg 4 of same length and without spines; coxa 2 with 2–3 spines on dorsal and lateral aspect; coxae 3 each with one lateral spine; femur almost 4 times as long as broad, bearing slender lateral cement gland tube and 4 distal spines; tibiae 1 and 2 subequal in length; tibia 1 with 5 long spines in distal half, the distalmost sparsely plumose; tibia 2 with 4 long dorsal spines, distalmost sparsely plumose; some short ventral setae, concentrated in its distal quarter; tarsus two times as long as broad, with few short setae; propodus moderately curved, with about 16 short setae; propodus dorsally bearing 4 long setae; main claw short and robust, around 2/5 length of propodus.

Measurements: Trunk length 1.4; width 0.96 (across second crurigers); length of abdomen 0.31; length of proboscis: basal part 0.28; distal pyriform part 0.96; length of cheliphore 0.91. Article lengths of leg 3: coxa 1—0.30; coxa 2—0.28; coxa 3—0.19; femur 0.71; tibia 1—0.95; tibia 2—0.96; tarsus 0.14; propodus 0.56; main claw 0.17.

Female: In size and habitus similar to male, dorso-distal tubercles on crurigers often absent (as shown in figure 18), spines on ocular process shorter. Coxae 2 distinctly more robust than in male.

Remarks: E. raphiaster is the Eurycyde species collected most numerously in its wide distribution area, therefore it seems astonishing that previous descriptions lack many details. Possibly E. raphiaster is closely related to Eurycyde setosa Child, 1988 from the Philippines (Batan Island). Both agree in habitus as well as in the possession of dorsal tubercles on crurigers and first coxae. E. raphiaster is distingushed from this species by the lack of the numerous short hairs on the processes adorning the first coxae, the cement gland opening situated more distally, as well as in the absence of the several plumose spines in femur and tibiae 1 and 3.

E. raphiaster is a species of shallow water occurring from the tidal zone to a maximal depth of 91 m. A distinct preference for particular substrata was not recognized, although it was never found on the growth covering jetty piles or in pure stands of sea-grass in the Santa Marta region. Mature males (often ovigerous) and females occurred all year round.

Distribution: Amphi-atlantic, but the overwhelming majority comes from the Caribbean (see Stock 1986: 401). In the eastern Atlantic E. raphiaster is known from the Cape Verde Islands and Senegal ( Stock 1990: 209).

Figures

FIGURE 32. Eurycyde raphiaster Loman, 1912: A male dorsal, B female dorsal, C female lateral, D female cheliphore.

FIGURE 33. Eurycyde raphiaster Loman, 1912: A male lateral, B female palp, C female oviger, D distal articles 7–10 of female oviger, E distal articles 7–10 of male oviger, F male leg 3, G cement gland duct from male leg 3, H female leg 3.