Sheep crab

Loxorhynchus grandis

Classification

Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Superorder: Eucarida
Order: Decapoda
Infraorder: Brachyura
Family: Epialtidae
Genus: Loxorhynchus
Species: grandis

Pronunciation

How to pronounce Loxorhynchus grandis: /ˌlɒk.soʊˈrɪŋ.kəs ˈɡræn.dɪs/

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

Images

Plate P (Garth, 1958) by Garth, J.S. 1958. Brachyura of the Pacific coast of America. Oxyrhyncha. Allan Hancock Pacific Expeditions. 21(1–2): i–xii, 1–874.. Used under a CC BY 4.0 license.

Sheep Crab (9449408935) by U.S. Department of the Interior. Used under a CC BY-SA 2.0 license.

Loxorhynchusgrandis by wikipedia. Used under a Cc-by-sa-3.0 license.

Plate 29 (Garth, 1958) by Garth, J.S. 1958. Brachyura of the Pacific coast of America. Oxyrhyncha. Allan Hancock Pacific Expeditions. 21(1–2): i–xii, 1–874.. Used under a CC BY 4.0 license.

Sheepcrab 300 by wikipedia. Used under a Public domain license.

Sheep crab (Loxorhynchus grandis) 01 by Tewy. Used under a CC BY 2.5 license.

Summary

Loxorhynchus grandis, commonly known as the sheep crab, is the largest crab along the California coast. It exhibits a range of adaptations including camouflage during juvenile stages and specialized reproductive behavior, contributing to its ecological and commercial significance.

Physical Characteristics

The sheep crab has a tear-shaped carapace that is reddish, brown, or blue-green with short spines or tubercles. Males can grow over 9.6 inches (24 cm) across while females can reach 6.8 inches (17 cm).

Identification Tips

Look for the distinctive tear-shaped carapace with a wide rounded posterior, a sharply down-curved preorbital spine on the rostrum, and the long second pair of walking legs that exceeds the carapace width.

Habitat

Coastal waters from Cordell Bank, California to Punta San Bartolome, Baja California, at depths between 6 metres (20 ft) and 152 metres (499 ft).

Distribution

Found along the California coast and into Baja California, Mexico.

Diet

The sheep crab is a scavenger-generalist, feeding on algae, mussels, sea stars, small crabs (including juvenile sheep crabs), and dead fish.

Life Cycle

Undergoes a terminal molt upon reaching sexual maturity, after which it ceases to grow. Young crabs are free-swimming plankton before settling and developing.

Reproduction

Sheep crabs are gonochoric, forming aggregations for mating. Males grasp females to deliver sperm, which females can store for later. Broods can range from 125,000 to 500,000 eggs, which are externally attached to the female until ready to hatch.

Predators

Preyed upon by sea otters, cabezon, California sheephead, octopus, sharks, bat rays, California sea lions, and larger sheep crabs.

Ecosystem Role

As scavengers, they play a role in the nutrient cycle of their marine environment by consuming detritus and recycling nutrients.

Economic Impact

Commercial fishery for sheep crabs developed in the late 1970s, relying on their claws and whole bodies for market. The fishery peaked in 1988, but has since diminished due to regulations.

Evolution

Fossils from the late Miocene epoch suggest this species dates back at least 11.63 to 5.333 million years.