The carapace overlaps almost
the entire first abdominal segment dorsally, and ends with a median
spine. The posteroventral margin of the carapace is rounded,
a spine. Has small supraorbital spines (less well-developed
in other Gnathophausia species). No
antennal spine; branchiostegal
spines inconspicuous. Rostrum is shorter in proportion to
in larger individuals than in smaller, and has many small teeth along
dorsal margin anterior of the eyes. Carapace has a high,
crest just behind the rostrum, and a dorsal keel (ridge) which begins
posterior to the crest. A lateral keel runs longitudinally
the carapace near the ventral margin, ending just anterior to the
margin. A vertical groove runs from the anterior end of this
dorsally to the base of the rostrum, and a second groove angles back
the anterior end of the lateral keel up to nearly the dorsal midpoint
the carapace. Antennal scales are separated into a proximal
distal region by an articulation. The apical spine on the
of the proximal part of the scale reaches to about the middle of the
part (or to the end of the distal part in small individuals).
without a mid-dorsal ridge or posterior-directed mid-dorsal
The second abdominal segment has a transverse groove on the dorsal
The anterior lobe of the ventral pleural plates is absent from smaller
specimens or rounded and smaller than the posterior lobe in large
The posterior lobe is pointed in segments 2-5. Sixth
appears to be divided into two parts; anterior portion with platelike
and posterior portion with posteroventral spines. Body length
including rostrum) to 10.2 cm.
Gnathophausia childressi Casanova,
Common name(s): Childress'
benthopelagic opossum shrimp
Lophogastridae (or Gnathophausiidae)
|Gnathophausia childressi (captured
at 1900 m depth, San Clemente
|(Photo by: Jim Childress)
How to Distinguish from
This species is very similar to Gnathophausia affinis,
also rare and found only in the Atlantic Ocean. It differs
affinis by having: Only one lateral keel on the
of two; a longer carapace which completely covers the last thoracic
and the dorsal groove on the telson is narrow anteriorly. Of
local species, it differs from G. gracilis by
having no dorsal keel
on the abdominal segments, from N. ingens
and N. gigas
by having no posteroventral spine on the carapace, and from G.
and G. longispina because the lateral keel on the
not curve dorsally as it approaches the posterior margin of the
the San Clemente Basin and East Cortez Basin, CA. Not seen in
Santa Catalina basin.
Bathypelagic, living in the
benthic boundary layer (within a few tens of meters of the
Captured within 0.3m of bottom.
History: This species
seems to stay in the benthic boundary layer of the bathypelagic zone,
particulate abundance is higher than that in the main water
The fact that they are benthopelagic may explain why they have been so
rarely caught--they are too near the bottom to be caught with a
trawl, yet do not rest on the bottom so are rarely caught with benthic
trawls. According to Childress, they can be relatively common
the regions where they occur, but just off the bottom. The
of this species are smaller and less chitinized than those of most
This has been interpreted to indicate that this species feeds at least
partly on the flocculent material in the water instead of by predation.
Casanova, Jean-Paul, 1996. Gnathophausia childressi,
species, a mysid from deep near-bottom waters off California, with
on the mouthparts of the genus Gnathophausia.
Journal of Crustacean
Biology 16:1 192-200
Childress, J.J., D.L. Gluck, R.S. Carney, and M.M. Gowing,
Benthopelagic biomass distribution and oxygen consumption in a deep-sea
benthic boundary layer dominated by gelatinous organisms.
and Oceanography 34: 913-930
General Notes and
Observations: Locations, abundances,
Another photo of this species by Jim Childress. These photos
are some of the only ones extant of this species shortly after capture.
Authors and Editors of Page:
Dave Cowles (2006): Created original page