# Northern Bay Mussel (*Mytilus trossulus*) The Northern Bay Mussel is a small, tasty shellfish that lives in the ocean. They have strong shells and can be found clinging to rocks in coastal areas. - **Category:** [Invertebrate](https://www.snappit.app/explore/categories/invertebrate) - **Rarity:** Common - **Danger:** 1/5 · Very low - **Habitat:** Coastal areas ![Northern Bay Mussel](https://commons.wikimedia.org/w/index.php?title=Special:Redirect/file/Mytilus_trossulus_Gould_1856_pl41_fig567.png&width=800) Photo: Augustus Addison Gould (1805-1866), Public domain · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Mytilus_trossulus_Gould_1856_pl41_fig567.png) ## Appearance The Northern Bay Mussel is a peculiar insect with a hard, two-part exoskeleton that strikingly resembles a dark blue or black mollusc shell. Its flattened, oval body, often adorned with faint growth rings, allows it to blend seamlessly into rocky coastal environments, making it hard to distinguish from actual mussels. ## Taxonomy - **Kingdom:** Animalia - **Phylum:** Mollusca - **Class:** Bivalvia - **Order:** Mytilida - **Family:** Mytilidae - **Genus:** Mytilus ## Interesting facts - It creates strong, silky threads to anchor itself firmly to underwater surfaces. - Some Northern Bay Mussels change sex, starting male then becoming female! - Their shell-like appearance helps them perfectly mimic real mussels on the seafloor. - This insect's tough, two-part casing offers amazing protection from hungry predators! ## Special abilities - **Super Sticky Anchors:** Northern Bay Mussel can cling securely to rocks because of specialized adhesive pads on its legs that help resist strong ocean currents. - **Microscopic Meal Filter:** Northern Bay Mussel has fine, comb-like bristles that help them filter tiny plankton and algae from the water. - **Underwater Breath:** Northern Bay Mussel can breathe efficiently underwater because of feather-like gills tucked beneath its shell-like exoskeleton. ## Measurements & details - **Size:** 15-40 mm - **Lifespan:** 365-730 days - **Leg Count:** 6 ## Diet & Feeding This amazing insect filters tiny food particles from the water, helping to keep the aquatic environment clean. - **Primary Foods:** Phytoplankton, Zooplankton, Diatoms, Detritus, Algae - **Foraging Method:** Filter feeding ## Ecological connections - **Eats:** [Ochre Sea Star](https://www.snappit.app/explore/ochre-sea-star) (*Pisaster ochraceus*) — A key predator of mussel beds in rocky intertidal zones. - **Hunts:** Frilled Dogwinkle Snail (*Nucella lamellosa*) — Hunts and consumes mussels, drilling through their shells for food. - **Eats:** Red Rock Crab (*Cancer productus*) — Crushes the shells of mussels and other intertidal invertebrates. - **Eats:** [Glaucous-winged Gull](https://www.snappit.app/explore/glaucous-winged-gull) (*Larus glaucescens*) — Drops mussels from height to break their shells for consumption. ## 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. - [Filter Feeder](https://www.snappit.app/explore/traits/filter-feeder): Filter feeders obtain nutrients by straining suspended food particles and small organisms from water. - [Herbivorous](https://www.snappit.app/explore/traits/herbivorous): This trait characterizes organisms whose diet consists entirely or primarily of plant material. - [Longevous](https://www.snappit.app/explore/traits/longevous): This trait characterizes organisms with an exceptionally long lifespan compared to others of their kind. - [Coastal](https://www.snappit.app/explore/traits/coastal): Coastal habitats are dynamic environments located along the interface between land and sea, influenced by tides, waves, and saltwater. - [Armored](https://www.snappit.app/explore/traits/armored): Armored describes animals protected by a hard, external covering or shell for defense. - [Keystone Species](https://www.snappit.app/explore/traits/keystone-species): Describes a species whose presence and role have a disproportionately large effect on its environment. - [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 - [Insects](https://www.snappit.app/explore/collections/insects) ## Safety **Danger:** 1/5 · Very low Don't touch or eat mussels you find on the beach without asking an adult first. ## Frequently Asked Questions ### How to identify Northern Bay Mussel? Compare the overall shape, opening, spiral, ribs, hinge and surface sculpture. Beach shells often lose the colors and sharp edges they had on the living animal, so shape does most of the work. Seashell Identifier: upload a photo and compare the visible details. ### How big is Northern Bay Mussel? 15-40 mm ### How long does Northern Bay Mussel live? 365-730 days ### What does Northern Bay Mussel eat? This amazing insect filters tiny food particles from the water, helping to keep the aquatic environment clean. ### Where is Northern Bay Mussel usually found? Coastal areas ### How does Northern Bay Mussel hunt? Filter feeding ### How many legs does Northern Bay Mussel have? 6 ## 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: [Northern Bay Mussel: Facts & Places to See — Snappit](https://www.snappit.app/explore/northern-bay-mussel)