Cancer irroratus

Say, 1817

Atlantic rock crab, peekytoe crab

A -sized marine crab to the western North Atlantic, ranging from Iceland to South Carolina. reach 133 mm width and can live up to 8 years. The occupies depths from intertidal zones to 790 m. It has become commercially significant as the 'peekytoe crab' and has established non-native in Iceland via ballast water transport.

Cancer irroratus by (c) Leïla Brunner, some rights reserved (CC BY), uploaded by Leïla Brunner. Used under a CC-BY license.

Cancer irroratus (Atlantic Rock Crab) (27460651671) by Plant Image Library. Used under a CC BY-SA 2.0 license.

Atlantic Rock Crab (Cancer irroratus) - Witless Bay, Newfoundland 2019-08-09 by Ryan Hodnett. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Cancer irroratus: /ˈkaŋ.kɛr i.roʊˈrɑː.təs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from the Jonah crab (Cancer borealis) by purplish- spots on the (versus in C. borealis) and smooth-edged marginal on the carapace (denticulate in C. borealis). Carapace width reaches 133 mm. Males range 8–127 mm, females up to 113 mm.

Images

Habitat

Marine rocky from above the low tide to 790 m depth. Found on hard substrates including rocky areas and tilted pools. Reproductive move to shallow waters during breeding season.

Distribution

range: western North Atlantic from Labrador and Iceland to South Carolina. Non-native established in Iceland and eastern North Atlantic, where it has become the most abundant brachyuran in southwest Iceland as of 2014.

Seasonality

Molting occurs primarily April–July. Reproductive season June–September, with females laying during this period.

Diet

Feeds on mollusks (mussels, clams), , sea urchins, and other crabs. Mussels are a particularly important energy source due to content.

Life Cycle

Females lay 125,000–500,000 between June and September. Larval stage lasts approximately two months, after which transition to benthic and begin hunting. Sexual maturity in males indicated by size >101 mm; females <70 mm are in early ovarian development.

Behavior

Uses enlarged to capture and manipulate . Engages in competitive interactions with lobster and Jonah crab in rocky . Reproductive migrate to shallow waters for mating. exhibit behavioral responses to light, pressure, and gravity cues.

Ecological Role

and scavenger that contributes to energy recycling in benthic . Serves as for lobsters, particularly during larval and soft-shell stages. May help regulate of shrimp and other crabs.

Human Relevance

Commercially harvested as 'peekytoe crab,' a culinary market that developed after 1997. Previously considered a nuisance to lobster fisheries due to theft. Subject to fishery regulations including size limits (102 mm) and prohibition on harvesting females.

Similar Taxa

Cancer borealisOverlaps in size and coloration; distinguished by (not purplish-) spots and denticulate (not smooth) marginal .
Carcinus maenas green crab with which C. irroratus interacts competitively in Newfoundland and other areas; differs in shape and color pattern.