Arctic lyre crab: Hyas coarctatus (Leach, 1815)
A very common lyre crab of shallow Arctic seas
Size
- Male carapace length 73 mm, width 58 mm
- Female carapace length 51 mm, width 40 mm
Color & Characteristics
- Dusky brick red above, whitish below
- Rostrum with two short, broad horns
- Carapace longer than broad, posterior part wider than anterior, with prominent hepatic lobe
- Dorsal surface with few large tubercles
Habitat & Distribution
- Mud, sand and gravel, 22-218 m
- Some biologists recognize separate subspecies of the Arctic lyre crab, as yet unconfirmed by genetics
Feeding
- Scavenger, grazer on algae, predator on hydroids, annelids, crustaceans and mollusks.
- The related H. lyratus has been observed to capture and eat small fishes and shrimp.
Life cycle
- Like other spider crabs (superfamily Majoidea), there is a terminal molt, after which they mate, carry eggs, then die
- Fertilization is internal
- Females carry a mass of 1500-8000 fertilized eggs under the abdomen
- Egg-bearing females reported from April to August, but the eggs do not hatch until nine to eleven months later
- Females can produce two sets of eggs in their lifespan
- Eggs hatch into pelagic zoeal stages and then metamorphose into megalops stages before settling to the sea floor
- Lyre crabs spawn in their second year after hatching
More Biology and Ecology
- Small individuals are decorators—they attach bits of algae or debris to the setae of the rostrum, carapace proper and walking legs
- The carapace of old individuals may be encrusted with barnacles, tube-building worms, and bryozoans
Page Author: Mary Wicksten
Created: August 5, 2010
