Biology ⁴

Biology/Natural History: Hides most of the day in crevices or under stones just above the high tide line. At night and at low tides in cool weather, forages throughout the intertidal zone. Is a scavenger, plus feeds on microscopic algae. This species is nearly terrestrial--it must keep its gills moist (by dipping the back of its abdomen into the water) but will drown if forced to stay underwater. This species is very tolerant to water loss. They are paler at night than during the day due to clustering and dispersal of chromatophores. Animals on dark backgrounds remain darker than do those on light backgrounds. Ovigerous females have been observed at Monterey Bay in March, May, and June.

Description ⁵

This isopod is a member of suborder Oniscoidea (uropodsterminal not ventral; body usually large and robust, mostly terrestrial, pleon generally with 5 free pleonites plus the pleotelson, antenna 1 with only 2-3 articles). Flagellum of antenna 2 is much larger, with more than 10 articles when mature. Up to 2.5 cm long. Eyes separated by one full eye diameter. Uropods are nearly half as long as the body, with basal segments several times as long as broad (photo).

Sources and Credits

1. (c) stonebird, some rights reserved (CC BY-NC-SA), http://www.flickr.com/photos/stonebird/7347659960/
2. (c) stonebird, some rights reserved (CC BY-NC-SA), http://www.flickr.com/photos/stonebird/7162446759/
3. (c) Scott Loarie, some rights reserved (CC BY), http://farm4.staticflickr.com/3693/12869877244_4dbc6a557f_o.jpg
4. (c) Rosario Beach Marine Laboratory, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/10456303
5. (c) Rosario Beach Marine Laboratory, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/10456301

More Info

• iNat taxon page
• Animal Diversity Web
• Biodiversity Heritage Library
• BOLD Systems BIN search
• BugGuide
• CalPhotos
• Global Biodiversity Information Facility (GBIF)
• NatureServe Explorer 2.0
• SeaLifeBase
• World Register of Marine Species

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