Phronima sedentaria

Description

General: Transparent hyperiid amphipod carries a barrel-shaped shelter made from the gelatinous tissues of salps and pyrosomes. Fifth pereiopods modified to claw-like shape to grasp barrel. Both males and females hijack pelagic tunicates as barrels, with females using the gelatinous host as food and shelter for her larvae. Thick, bristly uropods well developed.

Size: To 4.2 cm total length.

Reproduction: Females lay eggs within the barrel and larvae cohabit the barrel with their mother.

Geographic Information

Ocean range (global): Worldwide in tropical and temperate waters.

Habitat description: Epipelagic and mesopelagic.

Additional Information

Color: Transparent.

Diet: Zooplankton.

Key visual features: Swim in circles when in barrels. Also observed free-swimming.

References

Encyclopedia of Life

Tree of Life

World Register of Marine Species

National Center for Biotechnology Information

Scripps Institution of Oceanography. "Phronima sedentaria". Zooplankton Guide. Accessed 12/23/20. http://sio-legacy.ucsd.edu/zooplanktonguide/species/phronima-sedentaria

Aoki, M.N., C. Matsumoto-Ohshima, E. Hirose, and J. Nishikawa (2013). Mother-young cohabitation in Phronimella elongata and Phronima spp. (Amphipoda, Hyperiidea, Phronimidae). Journal of the Marine Biological Association of the United Kingdom. 93(6): 1553-1556.

Diebel, C.E. (1988). Observations on the anatomy and behavior of Phronima sedentaria (Forsskål) (Amphipoda: Hyperiidea). Journal of Crustacean Biology, 8(1): 79-90. https://doi.org/10.1163/193724088X00107

Laval, P. (1978). The barrel of the pelagic amphipods Phronima sedentaria (Forsskål) (Crustacean: hyperiidea). Journal of Experimental Marine Biology and Ecology, 33(3): 187-211. https://doi.org/10.1016/0022-0981(78)90008-4

Laval, P. (1980). Hyperiid amphipods as crustacean parasitoids associated with gelatinous zooplankton. Oceanography and Marine Biology Annual Review, 18: 11-56.

Marine Species Identification Portal. "Phronima sedentaria." Zooplankton and Micronekton of the North Sea. Accessed 10/28/20. http://species-identification.org/species.php?species_group=zmns&menuentry=soorten&id=370&tab=beschrijving.