well-developed, anterior margin has spines. Rostrum
elongated, triangular in cross-section. Exopod
is divided by a suture
near the apex.
scale large, with a distinctly isolated distal
part separated from the proximal
part by a more or less well-developed articulation.
end of antennal
scale smooth, with 1 large spine on the external
3-8 widened, lanceolate,
with 3 spines only on the distal
part of the inner margin and 1 spine in the middle of the inner margin.
plates of the sixth abdominal
segment not knitted together ventrally.
G. longispina: Keel
along ventrolateral margin of carapace
as it approaches the posterior
end of the carapace.
There is no spine at the posteroventral margin of the carapace
(that margin is rounded). The mid-dorsalkeel
is not interrupted nor serrated,
and continues out onto the rostrum. No spines on the mid-dorsalkeel
segments, or only small, posteriorly-directed
spines. Two spines on each side of the anterior pleura
of the sixth abdominal
spine missing or very small. Large, triangular and
spine. Spine on antennal
scale projects well beyond the end of the scale
and is serrated
on both sides. Rostrum
up to 70% of the body length. Pleural
plates of sixth abdominal
segment have two lobes--anteroventral and posteroventral. The
(sometimes called seventh) abdominal
segment has a well-developed spine which is associated with the base of
Body length (to orbit)
up to at least 5 cm.
Gnathophausia longispina G. O. Sars,
|Gnathophausia longispina in a petri
dish. Captured in
midwater off Oahu, HI
|(Photo by: Jim Childress,
How to Distinguish from
This species is most similar to G. zoea, which has
a similar structure
on the antennal
scale, a similar pattern of keels
on the carapace,
and similarly structured abdominal
segments. However, G. zoea has rounded branchiostegal
spines and no spine on the end of the last abdominal
segment which is associated with the telson.
Central and western
tropical and warm north temperate Pacific
150-500 m. Shallower
than other Gnathophausia species, may be in the
Mesopelagic or shallow bathypelagic.
Seems to always be found near land.
species is by far the lightest-colored species of Gnathophausia
that I have seen. The light coloration is probably correlated
the shallow depth that the species is found at. The rostrum
species, as in many Gnathophausia, is
proportionately larger in
small individuals, as are the spine on the antenna and the
spine. The posterior lobe of the pleuron on the second
segment forms a spine which is longer in mature males than in mature
Clarke, W.D., 1962. The genus Gnathophausia
Crustacea), its systematics and distribution in the Pacific
Ph.D. thesis, University of California, San Diego, Ca. 251
Ortmann A.E., 1906. Schizopod Crustaceans in the
States National Museum- the Families Lophogastridae and Eucopiidae.
Printing Office, Washington DC
General Notes and
Observations: Locations, abundances,
Authors and Editors of Page:
Dave Cowles (2006): Created original page