Overview

Comprehensive Description

Biology/Natural History: This species seems to stay in the benthic boundary layer of the bathypelagic zone, where particulate abundance is higher than that in the main water column. 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 midwater trawl, yet do not rest on the bottom so are rarely caught with benthic trawls. According to Childress, they can be relatively common in the regions where they occur, but just off the bottom. The mandibles of this species are smaller and less chitinized than those of most other Gnathophausia. This has been interpreted to indicate that this species feeds at least partly on the flocculent material in the water instead of by predation.

Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

The carapace overlaps almost the entire first abdominal segment dorsally, and ends with a median posterodorsal spine. The posteroventral margin of the carapace is rounded, without a spine. Has small supraorbital spines (less well-developed than in other Gnathophausia species). No antennal spine; branchiostegal spines inconspicuous. Rostrum is shorter in proportion to body size in larger individuals than in smaller, and has many small teeth along the dorsal margin anterior of the eyes. Carapace has a high, sharp dorsal crest just behind the rostrum, and a dorsal keel (ridge) which begins just posterior to the crest. A lateral keel runs longitudinally along the carapace near the ventral margin, ending just anterior to the posteroventral margin. A vertical groove runs from the anterior end of this keel dorsally to the base of the rostrum, and a second groove angles back from the anterior end of the lateral keel up to nearly the dorsal midpoint of the carapace. Antennal scales are separated into a proximal and a distal region by an articulation. The apical spine on the outer margin of the proximal part of the scale reaches to about the middle of the distal part (or to the end of the distal part in small individuals). Abdomen without a mid-dorsal ridge or posterior-directed mid-dorsal spines. The second abdominal segment has a transverse groove on the dorsal side. The anterior lobe of the ventral pleural plates is absent from smaller specimens or rounded and smaller than the posterior lobe in large individuals. The posterior lobe is pointed in segments 2-5. Sixth abdominal segments appears to be divided into two parts; anterior portion with platelike pleura and posterior portion with posteroventral spines. Body length (not including rostrum) to 10.2 cm.
Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Distribution

Geographical Range: Collected from the San Clemente Basin and East Cortez Basin, CA. Not seen in the Santa Catalina basin.

Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Physical Description

Type Information

Allotype for Gnathophausia childressi Casanova, 1995
Catalog Number: USNM 268484
Collection: Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology
Sex/Stage: male;
Preparation: Alcohol (Ethanol)
Collector(s): J. Casanova
Year Collected: 1981
Locality: California, United States, North Pacific Ocean
Depth (m): 2080 to 2080
  • Allotype:
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Holotype for Gnathophausia childressi Casanova, 1995
Catalog Number: USNM 268483
Collection: Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology
Sex/Stage: female;
Preparation: Alcohol (Ethanol)
Collector(s): J. Casanova
Year Collected: 1981
Locality: California, United States, North Pacific Ocean
Depth (m): 2080 to 2080
  • Holotype:
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Look Alikes

How to Distinguish from Similar Species: This species is very similar to Gnathophausia affinis, which is also rare and found only in the Atlantic Ocean. It differs from G. affinis by having: Only one lateral keel on the carapace instead of two; a longer carapace which completely covers the last thoracic segment, and the dorsal groove on the telson is narrow anteriorly. Of the 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. zoea and G. longispina because the lateral keel on the carapace does not curve dorsally as it approaches the posterior margin of the carapace.
Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Ecology

Habitat

Depth range based on 2 specimens in 1 taxon.

Environmental ranges
  Depth range (m): 2080 - 2080
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Depth Range: 1708-1940 m

Habitat: Bathypelagic, living in the benthic boundary layer (within a few tens of meters of the bottom). Captured within 0.3m of bottom.

Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!