Marbefia

Two females and a male (right) of the new genus Marbefia. The male copepod is slightly shorter and has modified antennules which are used to clasp onto the female during mating.

A new genus of benthic harpacticoid copepod has been named Marbefia to honour the outstanding contributions of MarBEF to our knowledge of marine biodiversity. Currently this genus consists of only 1 species, which was first described by Hammond in 1968 as Pseudonychocamptus carthyi. Since 1968 this species was recorded only once more in literature and the male had remained unknown. MarBEF scientists now recognised the classification error and renamed it Marbefia carthy.

Marbefia is a small, slender copepod, highly ornamented, with a dense covering of fine hairs. Like all copepods, they have 5 pairs of head appendages (antennules, antennae, mandibles, maxillules and maxillae). The thorax which is fused to the head bears 7 appendages, maxillipeds, four legs, the modified fifth legs and the so called sixed legs. Marbefia displays several sexual dimorphisms, with females (0.7 mm) being larger than males (0.58 mm), and differences in the appendages. Distinguishing for Marbefia is the difference between the swimming legs of males and females, with males missing the inner seta on leg 3 and 4 (see fig 2).

Marbefia is currently known from the Southern North Sea and the Isles of Scilly. It usually is present in shallow pools under piers and in the presence of jellyfish.