Anoplodactylus batangensis (Helfer, 1938)

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 : 88-90

Anoplodactylus batangensis (Helfer, 1938)

Fig. 47

Pycnosoma batangense, Helfer, 1938: 174 .

Anoplodactylus batangensis (Helfer, 1938) :—Stock 1968: 54, (lit., synonymy). Arnaud 1973: 957. Stock 1974: 17. Child

1975: 191. Stock 1975: 133. Stock 1975: 1082. Child 1977: 444. Child 1979: 50. Stock 1979: 27. Child 1982: 368.

Child 1988: 14. Stock 1989: 95. Child 1990: 311–335. Müller 1990d: 283. Müller 1992: 47.

Material: 6.— 3 males (1 ov.), 1 juv. ( MNHN), Thalassia , 2 m, 1.VIII.1985 . 2 fem. (gravid) ( SMF 1176 ), 10.IX.1985 . 1 male (ov.) ( SMF 1177 ), Thalassia , 3 m, 9.X.1985 . 2 males (1 ov.), 2 fem. ( ZMA 3355 ), Thalassia , 12.XII.1985 . 2 males (1 ov.), 3 fem. (gravid), 2 juv. ( SMF 1178 ), Thalassia ,, 1–2 m, 13.I.1986 .

7.— 4 males, 2 fem. (gravid) ( SMF 1179 ), Syringodium , 3 m, 12.XII.1985 .

8.— 3 juv. ( SMF 1180 ), upgrowth on ropes and fishing lines, between jetty piles, 0.5–6 m, 2.VIII.1985 .

9.— 1 juv. ( SMF 1181 ), under stones, 0–1 m, 28.I.1986 .

10.— 1 juv. ( SMF 1182 ), algae covering rocks, lower mesolittoral, 10.V.1985 .

17.— 1 juv. ( SMF 1184 ), on Cnidoscyphus on rock, lower mesolittoral, 2.X.1985 . 4 juv. ( SMF 1185 ), short algae on blocks of rock, mesolittoral to ca. 0.5 m, 7.I.1986 .

19.— 9 males (4 ov.), 1 fem. (gravid) ( SMF 1186 ), Thalassia , 5 l of substratum, 0.5–4 m, 27.VI.1985 . 1 male, 1 juv. ( ZSM), Thalassia , 5 l of substratum, 0.5–4 m, 8.VII.1985 .

21.— 1 juv. ( SMF 1187 ), on Digenia simplex , 5 l of substratum, lower mesolittoral, 12.II.1986 .

34.— 1 juv. ( SMF 1188 ), under stones, ca. 0.5 m, 10.IV.1986 .

37.— 1 male, 1 fem. ( INVEMAR), on detritus, algae and hydroids, 6 m, 4.VI.1985 .

38.— 1 juv. ( SMF 1189 ), Thalassia , 0.5 m, 17.III.1986 .

40.— 5 males (2 ov.), 11 fem. (10 gravid), 5 juv. ( SMF 1190 ), Thalassia , 1–3.5 m, 8.VIII.1985 . 2 males (1 ov.), 8 fem. (6 gravid) ( SMF 1191 ), Thalassia , 2–4 m, 28.X.1985 .

42.— 1 juv. ( SMF 1195 ), coral rubble, 13 m, 28.II.1986 .

43.— 1 male (ov.), 1 fem. (gravid), 1 juv. ( ZSM), Thalassia , 1–1.5 m, 25.II.1986 .

44.— 1 male, 1 fem. (gravid) ( SMF 1196 ), Syringodium , 1.5–2 m, 25.II.1986 .

45.— 2 male (1 ov.), 1 fem. (gravid) ( ZSM), on algae, hydroids and bryozoans on rock, 6–10 m ,

25.IX.1985.

Description of male: Trunk oval, relatively robust, segments 3 and 4 fused. Crurigers about as long as wide, separated by 1/2 of their breadth, dorso-distally with a small tubercle. Ocular process two times higher than basal diameter, its distal half narrowing in form of a cone, eyes distinctly pigmented. Abdomen upright or directed obliquely backwards, twice as long as proximal diameter. Proboscis relatively long and nearly tubular, in its proximal fourth ventrally inclined, its distal region almost straight and directed horizontally.

Cheliphore slender, barely reaching tip of proboscis; chela twice as long as broad, both fingers short, distinctly curved and untoothed; movable finger with a seta on proximal exterior margin. Oviger 6-articled; 3 rd article the longest, 4 th article about as long as 5 th and 6 th together; terminal article shortest, cone-shaped; on articles 5 and 6 several short setae, which are mostly directed backwards.

Legs robust; coxae 1 and 3 of same length, 2/3 the length of coxa 2; femur the longest and most robust article, without any bumps and few setae only; cement gland duct in a dorso-median position at the end of proximal half of femur, cement gland duct three times as long as its diameter, distally barely narrower and with fine transverse rings; tibia 1 1.3 times as long as tibia 2, both featuring a long dorso-distal seta; tarsus as long as broad; propodus with a well developed heel, distally bearing two robust spines; sole most often with 5 smaller spines and few short setae; no cutting lamella; main claw strongly curved, robust, 2/3 length of propodus; auxiliary claw absent.

Measurements: Length of trunk 0.69; width 0.46 (across first crurigers); length of abdomen 0.18; proboscis length 0.32; length of cheliphore scape 0.21; chela 0.11. Lengths of leg 3: coxa 1—0.13; coxa 2 - 0.21; coxa 3—0.13; femur 0.37; tibia 1—0.33; tibia 2—0.26; tarsus 0.08; propodus 0.31; end claw 0.20.

Female: Other than the secondary sexual characters, habitus like male.

Postlarva: Legs 4 mere stumps, no articulation. Total length 0.64.

Remarks: A. batangensis is characterized by the slender proboscis and therefore easily identified even as a postlarva. Relationships with other species are not clear: A. batangensis may be close to Anoplodactylus marshallensis Child, 1982 from the Marshall Islands (Eniwetok Atoll) in the Pacific. This species is habitus similar to A.batangensis , its proboscis is consideraly more robust, there is a short cutting lamella on distal part of propodal sole. Cement gland duct of both species quite similar, with transverse rings (cf. Child 1982: 274, Fig. 2a–f ). A. batangensis may be related to Anoplodactylus squalidus Clark, 1973 (incl. A. rimulus Child, 1988 ), a species widely distributed in the tropical Indo-Pacific. It is differentiated from batangensis by a somewhat variable, but distinctly more robust proboscis, a longer cement gland duct without transverse rings and a short distal cutting lamella on the propodal sole (cf. Child 1988: 60, Fig.3 ; Müller 1989: 127, figs. 45– 46 and Nakamura & Child 1988: 815, fig. 2G–I).

In the research region A. batangensis was one of the more frequent species and colonized mainly stands of sea-grass and vegetation of algae. The depth distribution was from the mesolittoral to 13 m. Ovigerous males were collected mainly in the rainy season in months VII–XII. Just 2 specimens (in months I and II each) were found in the dry season. The salient gap in months III–V, during which neither ovigerous males nor females with eggs in their ovaries were found, makes a correlation of the reproductive period with the dry season very probable.

Distribution: Pan-tropical. Numerous samples, mostly from the western Atlantic, were recorded. Here the species is reported from Florida to the south, to Colombia and Venezuela (cf. Stock 1986: 403).

Figures

FIGURE 2. Achelia gracilis Verrill, 1900. A, male dorsal, B, female dorsal, C, male lateral, D, male cheliphore, E, female oviger, F, male oviger. Scale 200 mm for A–C, 50 mm for D–E, 100 mm for F.

FIGURE 3. Achelia gracilis Verrill, 1900. A, male palp, B, leg 3 of male, C, leg 3 of female, D, cement gland duct, E, tarsus and propodus of male leg 3.

FIGURE 47. Anoplodactylus batangensis (Helfer, 1938): A male trunk dorsal, B male trunk with oviger lateral, C postlava dorsal, D postlarva ventral, E male proboscis ventral, F male chela, G distal three articles of male oviger, H male leg 3, I propodus and tarsus of male leg 3, J cement gland duct of male leg 3.