Haminoea exigua

Haminoea exigua Schaefer, 1992

• Haminaea exigua Schaefer, 1992

Description
This is a small species of Haminoea (hence the specific name) that does not usually exceed 12-14 mm in length. The general coloration of the body is slightly yellowish but this color is masked by the numerous brown, red, orange and whitish scores and spots found throughout the body. The brown spots are irregular and sometimes are branched; in some specimens they are very abundant and lead to a general darkening of the body. White scores (iridiophores) may join together forming large irregular spots on the visceral mass area covered by the shell; on the head, these white scores are more abundant in the anterior margins of head shield. Orange scores (xanthophores) can also be seen mainly in the visceral mass area covered by the shell, which is semitransparent, and are very abundant and apparent in juvenile specimens. The head shield is slightly bilobulated in the anterior side while its posterior lobes are well developed. The eyes are at the center of two depigmented areas of the head shield, which is generally dark due to irregular brown spots. The parapodial lobes are quite short and cover only partially and laterally up to the middle of the shell when the animal is moving. The shell and visceral mass are truncated on the rear side. The posterior paleal lobe protrudes slightly behind the shell. The foot runs ventral until half of the shell, it is semi-transparent but also has brown spots and scattered white scores.

Biology
So far, the few observations of living individuals of this species have been in shallow marine sediments consist of fine sand, shell sand (Schaefer, 1992), among masses of algae such as Halopteris scoparia (Sanchez-Moyano et al. 2000) and also from rhizomes of Posidonia oceanica. The spawns have been observed in aquariums at Vienna University and consist of a C-shaped or slightly coiled ribbon of about 10 mm in length and 3.5 mm of height, containing eggs of about 60 microns in diameter; larvae hatch after six and a half days after spawning and they have an average length of 100 microns (Schaefer, 1992).

Etymology

• Exigua. From Latin “Exiguus”, a little, a bit of, dreary, meager, scanty, petty, short, poor, small.

Distribution
This species is known only from the northern Adriatic Sea (peninsula of Istria in Croatia and the port of Ancona in Italy; Schaefer, 1992), from the Strait of Gibraltar, from Cape of Palos on the Mediterranean levantine coast of the Iberian Peninsula (Cervera et al., 2004) and from the coast of Catalonia, where it has been observed in different locations of the Costa Brava (Girona), in Mataro (Barcelona) and in Torredembarra (Tarragona).

Known georeferenced records of the species: Haminoea exigua
Sources:
: OBIS : GROC 2010-2011 : Enric Madrenas : João Pedro Silva : Bernard Picton : GBIF.ORG	: OPK : VIMAR : Manuel Ballesteros. : M@re Nostrum : Altres fonts : Marine Regions

Abundance

Western Mediterranean:	★☆☆☆☆
Eastern Mediterranean:	★☆☆☆☆
Atlantic Ocean:	☆☆☆☆☆