THE MARINE FAUNA OF THE BLACKWATER ESTUARY 31
Cryptoniscidae
Liriopsis pygmaea (Rathke)
Specimens of the free-living stage of this parasitic isopod were
occasionally taken in the Blackwater at Maldon (May-June 1961).
Order Amphipoda
Amphipods are commonly recorded from the sea shore and
bottom. Some specific identifications have been made but much
of the material collected has not been identified.
Lysianassidae
Orchomenella nana (Krøyer)
Occasionally taken in bottom samples. Station N.2 (1960).
Ampeliscidae
Ampelisca brevicornis (A. Costa)
Atylidae
Nototropis (Paratylus) vedlomensis (Bate & Westwood)
One record only; from station 2a.4 in 1960.
Amphiphoidae
Amphiphoe rubricata (Montagu)
One record only; off Pewet Island, Bradwell, in 1964.
Gammaridae
Gammarellus homari (Fabricius)
One record only; from fouling on a ship anchored in the
Blackwater (25.4.1960).
Cheirocratus sundevalli (Rathke)
One record in a dredge sample from station S.18 in 1960 and
another from station TL.4, 3.1.1961.
Melita obusata (Montagu)
Occasional records from bottom samples.
Gammarus locusta (Linne)
Common on all stony and shelly shores and amongst seaweeds.
Decoy Point and Osea Island seaward to St. Peter's Flats and
Colne Point. Also found below low water mark in this area.
Marinogammarus marinus Leach
The only definite identification was made from amphipods
collected from amongst Mytilus edulis on Clacton Pier, but the
species is probably common in the area.
Dexaminidae
Dexamine spinosa (Montagu)
Commonly occurring in samples of the benthos taken from
bottoms of clean shell or stones. Distributed from the Thirslet
area seawards.