Marine Invertebrates

Invertebrate animals that live in marine environments.

Articles with this tag: 5 Updated: May 13, 2026

Articles with this tag

Amphipod (Amphipoda): biology, diversity and ecological roles Amphipod Amphipods are a diverse order of mostly small, carapace-less crustaceans found in marine, freshwater, cave and terrestrial habitats; many are scavengers or detritivores and importa…

Bivalve (Bivalvia): two‑valved molluscs — overview, anatomy, ecology, uses

Bivalve (Bivalvia): two‑valved molluscs — overview, anatomy, ecology, uses Bivalve Bivalves are aquatic molluscs with two hinged shells. This article summarizes their anatomy, feeding, habitats, reproduction, evolution, ecological roles and human uses.

Chelicerata: anatomy, evolution, diversity and ecological roles Chelicerata Chelicerata are a major arthropod subphylum including arachnids and horseshoe crabs, defined by chelicerae and a two-part body; they have a long fossil record and play key ecologic…

Chondrophore (Porpitidae): colonial, surface‑dwelling hydrozoans Chondrophore Chondrophores (family Porpitidae) are small colonial hydrozoans that float at the ocean surface. Known members include Porpita porpita and Velella velella; they resemble jellyfish…

Coleoidea — the modern shell‑less cephalopods

Coleoidea — the modern shell‑less cephalopods Coleoidea Coleoidea is the cephalopod subgroup that includes octopuses, squids and cuttlefish, distinguished by reduced or internal shells, advanced nervous systems, and diverse marine ecolo…