(Forskål, 1776)
Description
Definitive nectophore [Hippopodius hippopus ]: horseshoe- shaped. The four roundeddorsal knobs vary in size and the inner two may be almost imperceptible (or absent, as in the very first definitive nectophore to be developed). The nectosac is relatively large, and a rête, which is largest in the younger nectophores, is present on the ventral canal.
Juveniles: the nectosac of larval nectophore [H.hippopus-larval] has only two radial canals. A rête is present in the younger nectophore.
Whole polygastric stage [H.hippopus-polygastric ], and photo [H.hippopus-photo].
Colour
The nectophores emit bright bioluminescent flashes when stimulated. The definitive nectophores often go opaque when preserved.
Size
Nectophore up to 220 mm in diameter.
Depth range
Epipelagic species, mainly occurring at depths down to 300 m.
Remarks
Complete polygastric phases are often found in net collections.
Distribution in the North Sea
Northern North Sea.
World distribution
Hippopodius hippopus has a widespread distribution throughout the World’s oceans and the Mediterranean Sea.
[After Kirkpatrick and Pugh, 1984]