Oniscus entomon Linnaeus, 1758
Mesidotea entomon (Linnaeus, 1758)[3]

Saduria entomon is a benthic isopod crustacean of the family Chaetiliidae.[2][3] It is distributed along the coasts of the Arctic Ocean and of the northern Pacific Ocean. It is also found in the brackish Baltic Sea, where it is considered a glacial relict.[4] Moreover, it is present in a number of North European lakes, including Ladoga, Vänern and Vättern. It has been introduced into the Black Sea.[5]

Saduria entomon is one of the largest crustaceans in the Baltic Sea. The largest ones are found in the depths of the Gulf of Bothnia,[6] reaching a maximum length of nearly 9 cm (4 in).[4] S. entomon are sexually dimorphic, with males growing larger and maturing at larger sizes than females.[7] Most individuals die after reproduction, and the species might be functionally semelparous, but it is probably capable of iteroparity. Its lifespan is 3 years, possibly much longer.[7]

Saduria entomon is a predator that feeds on other benthic animals, such as Monoporeia affinis. It is also a scavenger and a cannibal.[4]


  1. ^ HELCOM Red List Benthic Invertebrate Expert Group (2013). "Saduria entomon" (PDF). HELCOM Red List of Baltic Sea. HELCOM. Retrieved 17 May 2016. 
  2. ^ a b "Saduria entomon (Linnaeus, 1758)". Integrated Taxonomic Information System. Retrieved February 1, 2006. 
  3. ^ a b c Guiry, Michael D. (2009). Schotte M, Boyko CB, Bruce NL, Poore GC, Taiti S, Wilson GD, eds. "Saduria entomon (Linnaeus, 1758)". World Marine, Freshwater and Terrestrial Isopod Crustaceans database. World Register of Marine Species. Retrieved 17 May 2016. 
  4. ^ a b c "Saduria entomon". Aquascope. Retrieved 20 June 2010. 
  5. ^ Y. Kvach (2009). "First report of Saduria (Mesidotea) entomon (Linnaeus, 1758) (Isopoda: Chaetiliidae) in the Black Sea" (PDF). Aquatic Invasions. 4 (2): 393–395. doi:10.3391/ai.2009.4.2.17. 
  6. ^ "Kilkki". The Baltic Sea Portal (in Finnish). Retrieved 20 June 2010. 
  7. ^ a b Haahtela, Ilpo (1990). "What do Baltic studies tell us about the isopod Saduria entomon (L.)?" (PDF). Annales Zoologici Fennici. 27: 269–278.