# Portly Spider Crab (*libinia emarginata*) The Portly Spider Crab is a large, friendly crab that loves to scuttle around the ocean floor. Its unique shape and colorful shell make it a fun creature to discover during beach walks! - **Category:** [Invertebrate](https://www.snappit.app/explore/categories/invertebrate) - **Rarity:** Common - **Danger:** 1/5 · Very low - **Snaps:** 6 - **Habitat:** Coastal waters and sandy ocean floors - **Also known as:** Portly Crab, Spider Crab ![Portly Spider Crab](https://inaturalist-open-data.s3.amazonaws.com/photos/19044/medium.jpg) Photo: Joey, CC BY 4.0 · [iNaturalist](https://www.inaturalist.org/photos/19044) ## Appearance The Portly Spider Crab has a triangular, spiky, pear-shaped carapace that is often covered in attached marine organisms. Its dull brown-green body blends with the seafloor, and it possesses ten long, slender, pointed legs. ## Taxonomy - **Kingdom:** Animalia - **Phylum:** Arthropoda - **Class:** Malacostraca - **Order:** Decapoda - **Family:** Epialtidae - **Genus:** Libinia ## Interesting facts - A group of these ocean crabs is sometimes called a "cast"! - Its spiky shell helps grip plants for awesome camouflage! - Spider crabs love a good feast of tiny dead animals! - They taste with tiny hairs found on their legs and claws! ## Special abilities - **Ocean Gardener:** Portly Spider Crab can attach seaweed and sponges to its shell, creating excellent camouflage from predators. - **Limb Regenerator:** Portly Spider Crab can re-grow lost legs or claws, which helps it recover from injuries or predator attacks. - **Underwater Builder:** Portly Spider Crab uses its strong, pointed legs to dig into soft sediments, helping it find food and hide. ## Measurements & details - **Lifespan:** 2-5 years - **Leg Count:** 10 - **Average Carapace Width:** Max 15 cm - **Average Leg Span:** Up to 50 cm - **Average Weight:** 100-500 g ## Diet & Feeding This crab munches on tiny plants and bits of dead stuff it finds on the ocean floor. - **Primary Foods:** Algae, Seaweed, Detritus, Small worms, Mollusks, Crustacean larvae - **Foraging Method:** Foraging ## Ecological connections - **Eaten by:** [Herring Gull](https://www.snappit.app/explore/herring-gull) (*Larus argentatus*) — A common seabird that preys on crabs in shallow waters. - **Eaten by:** [Blue Crab](https://www.snappit.app/explore/blue-crab) (*Callinectes sapidus*) — Larger blue crabs may prey on smaller spider crabs. - **Eats:** Sea Lettuce (*Ulva lactuca*) — This crab often grazes on green algae like sea lettuce. - **Eats:** [Blue Mussel](https://www.snappit.app/explore/blue-mussel) (*Mytilus edulis*) — Feeds on small mussels and other invertebrates. ## Traits - [Social](https://www.snappit.app/explore/traits/social): Social animals live in organized groups, cooperating for survival benefits such as foraging, defense, and raising offspring. - [Colorful](https://www.snappit.app/explore/traits/colorful): Colorful describes organisms or objects displaying a wide range of bright and distinct colors. - [Carnivorous](https://www.snappit.app/explore/traits/carnivorous): This trait identifies organisms whose diet consists entirely or primarily of animal tissue. - [Aquatic](https://www.snappit.app/explore/traits/aquatic): Aquatic habitats encompass environments where organisms live predominantly in water, including oceans, rivers, lakes, and wetlands. - [Marine](https://www.snappit.app/explore/traits/marine): Marine habitats encompass all saltwater environments of the Earth's oceans, supporting an immense diversity of aquatic life. ## Collections - [Invertebrates](https://www.snappit.app/explore/collections/invertebrates) ## Safety **Danger:** 1/5 · Very low Be careful near the water and always ask an adult for help! ## Frequently Asked Questions ### How to identify Portly Spider Crab? Look for fins, arms, tentacles, shells and body symmetry. Underwater light shifts colors, so structure and markings usually matter more than shade. Sea Creature Identifier: upload a photo and compare the visible details. ### How long does Portly Spider Crab live? 2-5 years ### What does Portly Spider Crab eat? This crab munches on tiny plants and bits of dead stuff it finds on the ocean floor. ### Where is Portly Spider Crab usually found? Coastal waters and sandy ocean floors ### How does Portly Spider Crab hunt? Foraging ### How many legs does Portly Spider Crab have? 10 ### What is the average Carapace Width of Portly Spider Crab? Max 15 cm ### What is the average Leg Span of Portly Spider Crab? Up to 50 cm ## Where to spot - [Bellevue Avenue Historic District](https://www.snappit.app/guides/places/bellevue-avenue-historic-district) — Rhode Island, US · Historic District - [Fort Revere Park](https://www.snappit.app/guides/places/fort-revere-park) — US · State Park - [Ocean Drive Historic District](https://www.snappit.app/guides/places/ocean-drive-historic-district) — US · Historic District - [Old Lyme Historic District](https://www.snappit.app/guides/places/old-lyme-historic-district) — Connecticut, US · Historic District - [Ravenswood Park](https://www.snappit.app/guides/places/ravenswood-park) — US · Nature Reserve - [Mytoi](https://www.snappit.app/guides/places/mytoi) — Massachusetts, US · Botanical Garden [View all places to see Portly Spider Crab](https://www.snappit.app/guides/where-to-see/portly-spider-crab) ## More Invertebrate - [Coral](https://www.snappit.app/explore/coral) - [Crab Spider](https://www.snappit.app/explore/crab-spider) (*Mecaphesa asperata*) - [Garden Spider](https://www.snappit.app/explore/garden-spider) (*Araneus diadematus*) - [Brown Recluse Spider](https://www.snappit.app/explore/brown-recluse-spider) (*Loxosceles reclusa*) --- Source: [Portly Spider Crab: Facts & Places to See — Snappit](https://www.snappit.app/explore/portly-spider-crab)