What are sea mice? - briefly
Sea mice are marine polychaete worms of the genus Chaetopterus, characterized by elongated, gelatinous bodies covered with bristly setae that resemble a mouse’s tail. They glide through coastal waters, feeding on detritus and plankton.
What are sea mice? - in detail
Sea mice are marine polychaete worms belonging to the family Terebellidae, most commonly represented by the species Chaetopterus variopedatus and Phyllochaetopterus spp. They inhabit shallow coastal waters, often among seagrass beds, sand, and detritus, where they construct tube‑like shelters from mucus and sediment particles.
Morphologically, sea mice possess a soft, elongated body segmented into distinct regions. The anterior segment bears a head with sensory palps and a pair of antennae, while the posterior segment carries numerous bristle‑like setae. These setae are covered with a transparent, gelatinous coating that reflects light, creating a shimmering appearance reminiscent of a mouse’s tail, hence the common name.
Feeding behavior relies on filter‑feeding mechanisms. Cilia on the setae generate water currents that draw planktonic particles and organic debris toward the mouth. The mucus coating traps food, which is then transported to the digestive tract. This strategy enables sea mice to exploit abundant microscopic resources in nutrient‑rich coastal zones.
Reproduction occurs seasonally, with adults releasing gametes into the water column. External fertilization yields planktonic larvae that undergo several developmental stages before settling and metamorphosing into benthic juveniles. The life cycle completes within a few months, allowing rapid population turnover.
Ecologically, sea mice contribute to sediment turnover and nutrient cycling. Their burrowing activity aerates the substrate, while their mucus secretions bind particles, influencing sediment stability. Additionally, they serve as prey for fish, crabs, and seabirds, integrating into the coastal food web.
Unique adaptations include bioluminescence in some species, where chemical reactions within the setae emit faint light when disturbed. This response may deter predators or facilitate communication during mating. The combination of flexible tube construction, efficient filter feeding, and occasional luminescence distinguishes sea mice among polychaete worms.