Anurida tullbergi resembles the more common Anurida maritima. Both species are bluish black in colour, have eyes with 5+5 ocelli and lack a furca and empodium on the foot (Fig. 1). However, the post-antennal organ (PAO) of Anurida tullbergi is elliptical with up to 30 vesicles (often asymmetrical on the same specimen - see Figs. 2, 3) (the PAO of Anurida maritima is small and circular with up to 11 vesicles). The largest specimen I have seen was 2.5 mm in length from a population collected from a sewage treatment works in London, a habitat in which Anurida tullbergi can reach very high population densities. Most inland records are indeed from sewage works although Anurida tullbergi is also found in the littoral zone and in waterside detritus, particularly if there is a saline influence. At present, there are no records from Wales.

Back to main page

Fig. 1 (above): Third legs of Anurida tullbergi collected from Bygrove Road Sewage Treatment Works, London in September 1955 by Peter Lawrence.

Fig. 2 (above): PAO with 23 vesicles (numbered arrows) and eye with five ocelli on the LEFT side of the head of the same specimen of Anurida tullbergi shown in Fig. 1.
Fig. 3 (below): PAO with 20 vesicles and eye on the RIGHT side of the head of the same specimen shown on Fig. 2.

Fig. 4 (above): Tip of the mandible of the same specimen of Anurida tullbergi shown in Fig. 1.

Fig. 5 (above): Tips of the maxillae of the same specimen of Anurida tullbergi shown in Fig. 1. These structures have become re-orientated; they would normally be arranged in parallel.