Marine Species Identification Portal : Mediterranean mud shrimp

(Petagna, 1792)

Diagnosis:
Rostrum ending in three teeth, the median long with a rounded apex ending in two spines; lateral teeth short, much shorter than half the median tooth, and separated from it by a deep groove. The median groove of the median tooth shallow. No spines on the ventral surface of the rostrum. Anterolateral margin of the carapace with a small but distinct tooth at the level of the eye. First pereiopods subchelate. In the adult male the palm is distinctly widened at the base of the fixed finger, so that the height of the chela is only slightly less than the length. Movable finger withblunt tubercles on the cutting edge but otherwise without tubercles, spines or ridges. Palm with two dorsal rows of spinules. Merus with a subdistal anterodorsal spine.

Type:
Type locality of Astacus pusillus: "Habitat in nostri maris arena, sed rarior". In nostri maris obviously stands for the seas near Naples, where Petagna lived. The whereabouts of the type material is unknown, it must be considered lost.
Type locality of Thalassina littoralis: "environs de Nice", dépt. Alpes Maritimes, S. France. Depository of type material unknown.
Type locality of Gebia lacustris: "Vive nel fango del lago Lucrino", west of Naples, Italy. Whereabouts of type material unknown.
Type locality of Gebia venetiarum: "del Veneto Estuario" "nelle nostre lagune" [= lagoon of Venice, Italy]. Depository of types unknown.

Geographical Distribution:
Eastern Atlantic region from Bretagne (Atlantic coast of France) to Mauritania (N.W. Africa), also in the entire Mediterranean and in the Black Sea.

Habitat and Biology:
Intertidal and subtidal zones down to about 45 m; sometimes in estuarine areas. The species makes simple Y-shaped burrows with 2 or more entrances in the mud or sandy mud.

Size:
Total body length about 4 to 6.5 cm.

Interest to Fisheries:
I found only a single reference indicating that the species is used for human consumption: Pesta (1918: 199) after reporting that the animals are used for fish bait in the Adriatic sea, remarked in parentheses "(Auch gegessen!) [= it is eaten!]." On the other hand there are numerous observations that the species is used as bait for fishing. So Chaud (1984: 169) remarked that on the coast of Cantabria (north coast of Spain ) "la capture de ces crustacés comme excellents appâts naturels pour la pêche assure la totalité des revenus pour quelques centaines de famille", and he also suggested that the species could well be used in the laboratory as a test animal for experiments. Cottiglia (1983: 79) stated that in Italy the species "viene esclusivamente usata come esca e come tale é molto ricerçata" (= it is only used as bait), more or less contradicting Pesta's statement that the animals are also used for human consumption. To obtain the animals, they are usually dug out of their burrows with spades. But when the mud is very soft, the water and the mud may be stirred with the feet so that the burrows become exposed or damaged and the animals flee and are easily picked up in the murky water. The most modern and efficient method, however, is that with a suction pump (the so-called yabbie pump; see under Callianassa australiensis), with which the contents of the burrow including the shrimp is pumped out in a quick and sudden movement. Finally there is a method by which through the application of a certain pressure the contents of the burrow is forced out; this so-called "casserole" method is described by Chaud (1984: 22) and used in Arcachon (S.W. France).

Mediterranean mud shrimp (Upogebia pusilla)