Anoplodactylus insignis ( Hoek, 1881 )

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 : 377-378

Anoplodactylus insignis ( Hoek, 1881)

Phoxichilidium insigne Hoek, 1881: 82-84 , plate XIV, figures 5–7.

Anoplodactylus insignis bermudensis Cole, 1904: 325- 327 , plate XX, figures 1–3, plate XXII, figures 21–29.

Anoplodactylus insignis calcaratus : Stock, 1986: 437- 438, figures 15a–15b.

Anoplodactylus insignis : Hedgpeth, 1948: 226-228, figures 28d– 28g; Stock, 1974: 1056-1058, figure 44; Child, 1992: 46-49, figure 21.

Material examined: Maranhão: ( UFPB.PYC–110) 1 ♀, Cedral, 19 Jul. 1982, coll. M.L. Christoffersen and I.A . Kanagawa.

Diagnosis: Trunk long, tenuous. Trunk segments 3 and 4 fused or partially fused. Lateral processes short, with setose dorso-distal tubercles that diminish in size in the posterior pairs. Ocular tubercle conical, directed obliquely forwards. Proboscis of male with a pair of medio-ventral alar protuberances. Scapus of chelifore with anterior setose tubercles. Chela setose without teeth on fingers. Legs with long ventro-distal tubercles on coxa 2, dorso-distal tubercles on femur and tibia 1. Cement gland opening into long groove. Propodus with distal tubercles, a pronounced heel with 3 spines, without a lamina. Auxiliary claws absent.

Distribution: Brazil (off Espírito Santo, Bahia, Maranhão, Pará, off Amapá), French Guyana, Suriname, Guyana, Trinidad and Tobago, Venezuela, Caribbean coast of Colombia, Curaçao, Guadeloupe, Gulf of Mexico, Bermuda, USA (Florida, Georgia, North Carolina) ( Stock, 1986, 1992; Child, 1992; Müller, 1993; Arango, 2000).

Depth: Up to 90 m deep.

Remarks: This species has tubercles on the cheliphores and long legs, which makes it easy to distinguish from the remaining species of the genus and from the species considered the closest to it, A. lentus Wilson, 1878 ( Child, 1992; Child, 1998b).

Stock (1986) proposed the variety calcaratus based on the difference in the size and number of the tubercles on the lateral processes and legs; the larger tubercles occur in calcaratus. This difference may represent an intraspecific or interspecific variation ( Arango, 2000). However, further analyses are necessary to determine the validity of this character and of this variation. In the specimens examined herein, the tubercles are short, differing from those described by Stock (1986) and Arango (2000), both from specimens coming from northern South America.

There are two recognized varieties of A. insignis , Anoplodactylus insignis var. bermudensis Cole, 1904 and Anoplodactylus insignis var. calcaratus Stock, 1986 , both having the same geographical and bathymetric distribution.

The variety proposed by Cole does not have lateroventral tubercles on the femur, nor segmentation between segments 3 and 4, but has the cement gland in the shape of a sieve ( Hedgpeth, 1948). The variety by Stock has a small anterior tubercle and a long posterior tubercle on the dorsal surface of coxa 1, a long tubercle in the distal region of the femur, and two small tubercles on the anterolateral and postero-lateral surfaces of the femur, some long tubercles on the proximal region of tibia 1, and a small tubercle on the dorsal margin of tibia 2 ( Stock, 1986).

The specimen examined by us is more similar to the material examined by Arango (2000), which differs from the variety by Stock for not possessing a dorsal tubercle on the lateral processes. However, the ocular tubercle is longer than that described by Arango, and a latero-distal tubercle is present on the femur and two dorsal proximal tubercles occur on tibia 1, as indicated by Stock, except that they are extremely reduced, being almost imperceptible on some legs. On tibia 2, the present specimen has two small tubercles with an apical seta at the distal apex, in a latero-distal position. The remaining characters agree with the description by Hoek (1881).

We agree with Arango (2000) and Stock (1986) in that a larger number of animals from different locations are necessary for deciding upon the intra- or interspecific value of these coxal morphological variations. Here we recorded this species for the first time in the State of Maranhão.