Hargeria rapax
| Hargeria rapax | |
|---|---|
_(15821496869).jpg) | |
| Female Hargeria rapax morph | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Clade: | Pancrustacea |
| Class: | Malacostraca |
| Order: | Tanaidacea |
| Family: | Leptocheliidae |
| Genus: | Hargeria |
| Species: | H. rapax |
| Binomial name | |
| Hargeria rapax (Harger, 1879) | |
| Synonyms[1] | |
| |
Hargeria rapax is a species of tanaid, a group of small crustaceans in the class Malacostraca physically similar to shrimp.
Taxonomic history
Hargeria rapax was originally described in 1879 as Leptochelia rapax by Oscar Harger.[1]
Description
Hargeria rapax is a small tanaid characterized by a rostrum with a downward curve that extends past the eyes. Male H.rapax first pair of appendages are large antenna, both of the secondary appendages have large chelae almost as large as the main body, followed by 6 pairs of pereopods then one pair of pleopods and ending with a uropod. Male H. rapax also have greatly reduced mouth parts that may be non-functioning.[2][3] Female H.rapax possess much smaller primary and secondary appendages as well as functional mouth parts.[3] Like most tanaidaceans H.rapax lacks a telson.[4]
Hargeria rapax constructs tubes made of silt and detritus held together by mucus to live in. These tubes can be attached to the surrounding benthos, flora, or tubes created by other species.[1][2]
Hargeria rapax are detritovores mainly consuming plant detritus and bottom dwelling diatoms.[5]
Habitat
Hargeria rapax lives in intertidal estuarine communities[6] and can most commonly be found in soft sediment shoreline habitats. H. rapax prefers to inhabit seagrass marshes made up of species like juncus and thalassia. This behavior may be attributed to the lower density of predators in this microhabitats.[6][3] H. rapax tends to be the most abundant in low elevation marsh edge sediments.[7]
Distribution
Hargeria rapax specimens have been observed from the Caribbean sea up the North American eastern coastline up to Canada.[8][4]
Main predators
The main predators of H. rapax include grass shrimp (Palaemon pugio),[9] Killifish,[10] and other similarly sized carnivorous fish.[5]
Life cycle
Hargeria rapax is a protogynous species meaning they start life as the female morph then transition to being male,[4] this male portion of the life cycle is short lived and may not feed at all as evidenced by the greatly reduced mouth parts.[2]
Hargeria rapax are external brooders which means they carry their eggs on the outside of their bodies, these eggs hatch into manca larvae that grow into reproductive females. After one or two broods the females molt into reproductive males.[11] Hargeria rapax gravid females can be found throughout the year but are especially abundant during February and March.[12]
References
- 1 2 3 "WoRMS - World Register of Marine Species - Hargeria rapax (Harger, 1879)". www.marinespecies.org. Retrieved 2026-04-26.
- 1 2 3 Heard, Richard W.; Lutz, Linda B. (1982). "Guide To Common Tidal Marsh Invertebrates Of The Northeastern Gulf Of Mexico". repository.library.noaa.gov.
- 1 2 3 Jarquín-González, Jani; Carrera-Parra, Luis F. (2019-08-19). "Redescription of Hargeria rapax (Harger, 1879) and description of H. chetumalensis a new species from the Mexican Caribbean (Crustacea, Peracarida, Tanaidacea, Leptocheliidae) based upon morphological and molecular evidence". PeerJ. 7 e7472. doi:10.7717/peerj.7472. ISSN 2167-8359. PMC 6705387. PMID 31489263.
- 1 2 3 Johnson, William (2012). Zooplankton of the Atlantic and Gulf Coasts. Johns Hopkins University Press. doi:10.1353/book.19394. ISBN 978-1-4214-0746-3.
- 1 2 Odum, W. E., & Heald, E. J. (1972). Trophic Analyses of an Estuarine Mangrove Community. Bulletin of Marine Science, 22(3), 671–738.
- 1 2 "Observations on the Natural History and Experiments on the Reproductive Strategy of Hargeria Rapax (Tanaidacea)". Journal of Crustacean Biology. 9 (4): 578–586. 1989-01-01. Bibcode:1989JCBio...9..578.. doi:10.1163/193724089X00593. ISSN 0278-0372.
- ↑ Whaley, Shannon D.; Minello, Thomas J. (December 2002). "The distribution of benthic infauna of a Texas salt marsh in relation to the marsh edge". Wetlands. 22 (4): 753–766. doi:10.1672/0277-5212(2002)022[0753:TDOBIO]2.0.CO;2. ISSN 0277-5212.
- ↑ Heard, Richard; Suárez-Morales, Eduardo; García-Madrigal, María Del Socorro (2004). "Records of and Observations on Tanaidaceans (Peracarida) from Shallow Waters of the Caribbean Coast of Mexico". Crustaceana. 77 (10): 1153–1177. Bibcode:2004Crust..77.1153H. doi:10.1163/1568540043166137. ISSN 0011-216X.
- ↑ Kneib, R.T. (January 1985). "Predation and disturbance by grass shrimp, Palaemonetespugio Holthuis, in soft-substratum benthic invertebrate assemblages". Journal of Experimental Marine Biology and Ecology. 93 (1–2): 91–102. Bibcode:1985JEMBE..93...91K. doi:10.1016/0022-0981(85)90151-0.
- ↑ Rozas, Lawrence P.; LaSalle, Mark W. (September 1990). "A Comparison of the Diets of Gulf Killifish, Fundulus grandis Baird and Girard, Entering and Leaving a Mississippi Brackish Marsh". Estuaries. 13 (3): 332. Bibcode:1990Estua..13..332R. doi:10.2307/1351924. JSTOR 1351924.
- ↑ "Rapax (Harger, 1879)". SeaLifeBase. Retrieved 2026-04-27.
- ↑ Sheridan, Peter F.; Livingston, Robert J. (December 1983). "Abundance and Seasonality of Infauna and Epifauna Inhabiting a Halodule wrightii Meadow in Apalachicola Bay, Florida". Estuaries. 6 (4): 407. Bibcode:1983Estua...6..407S. doi:10.2307/1351400. JSTOR 1351400.