Anoplodactylus monotrema Stock

Anoplodactylus monotrema Stock, 1979: 15-18, figs 4-5

Material. Adult ♀ (ZSM-A- 20071605); Casa Grisales, Bahia del Rodadero, Santa Marta; from stone with algae, 0.5 m, 10.12.2004 ; Juvenile ♂ (ZSM-A- 20071606); Playa Brava, Bahia de Taganga, Santa Marta; under stone, 0.5 m, 09.12.2004 .

Description (Figs 14, 15)

Living animal coloured yellowish to orange.Ganglia and gut well visible (Fig. 14B). Body oval, wide and robust (Figs 14A, 15A). Segmentation reduced (Fig. 15A). A small hair inserted distally on each segment. Walking legs also robust (Fig. 15A,G).

Eye tubercle flat, only slightly higher than wide (Figs 14B,C, 15D). Eyes strongly pigmented (Fig. 14C). Apical sense organ at the tip and 2 lateral sense organs present (Fig. 15D). Proboscis short and frontally flattened (Fig. 14D).

Abdomen of almost same height as eye tubercle; several hairs close to anus (Fig. 15A,E).

Chelifores 2-jointed, article 1 larger (Fig. 15B). Chelae relatively strong, located directly on top of mouth. Several small, pointed teeth at inner sides of the fingers (Fig. 15C), several hairs distributed all over them.

Ovigera with 2 to 3 articles; borders between them not well visible (Fig. 14D).

Coxa 1 with distal groove and 2 laterodistal hairs. Coxa 2 and 3 of same length, deprived of grooves and hairs. Femur 2× as long as coxa 3; distal protrusion with spine at tip. Tibia 1 similar to femur, distal protrusion with spine also present. Tibia 2 thinner than tibia 1. At ¾ of its length, a protuberance with spine is seen (Fig. 15G).Tarsus 2× as wide as high, with lots of hairs (Fig. 15F,H). Propodus robust, slightly curved (Figs 14E, 15F,H). Heel with 2 strong spines and 2 setae neighbouring them (Fig. 15I). Sole with medial row of small spade-shaped spines (Fig. 15F) and 2 lateral rows of hairs with rounded tips (Fig. 14E). Main claw 0.75× as long as propodus. Accessory claws very short and rudimentary (Fig. 15F,H).

Remarks. Our Colombian individuals of Anoplodactylus monotrema are well characterized by propodus characters and the absence of coxal spines. The heel spines described here are missing in earlier descriptions. Most remarkable are the spade-shaped spines of the sole that are of different form than those of the heel. Ovigera composed of 5 articles found in males of this species seem to be fully developed late in ontogeny, as our subadult male had only 2 to 3 articles that were hard to distinguish. This species has often been mixed with Anoplodactylus robustus (Dohrn 1881) .A good differential character, however, is the toothed finger of the chelae.

A. monotrema is distributed in the Western Atlantic Ocean from Florida to Brazil, and the first record for Colombia is that of Müller (1990).