Ragged Sea Hare

A ragged sea hare can resemble a loose tuft of growth until it starts crawling. Bursatella leachii has an irregular covering of branching, fleshy projections, often accompanied by dark blotches with bright blue centers. Its body varies in color, so the shaggy outline is more useful than expecting every animal to match one photograph. Unlike a shell-carrying snail, an adult has no visible external shell.

Documented local animals and eggs

This is a particularly strong addition to an Atlantic South Florida identification guide. Australian Museum Sea Slug Forum records describe living animals in Fort Pierce’s intertidal and shallow lagoon habitats in December 2008. Photographs from Lake Worth Lagoon, Riviera Beach, document adults laying eggs in November 2008. A separate February 2003 record shows animals and eggs in Boca Raton’s Intracoastal Waterway. Biscayne National Park also lists the species.

These are dated observations, not a promise that a present-day dive will encounter an aggregation. They support lagoon and sheltered nearshore coverage within the Vero–Key Largo corridor; they do not establish a sighting at every reef or at Vero Beach itself. The locality of each observation matters more than a general label such as “Florida Keys.”

Feeding and life history

Ragged sea hares graze on microbial and algal material, including cyanobacteria and diatoms. Their food is quite different from the animal prey pursued by many other marine snails. Keep that distinction in mind when watching a slug move across a film-covered bottom: movement alone does not reveal exactly what it is eating.

The eggs form a long cord containing capsules. After hatching, larvae enter the plankton before settling and developing toward the crawling adult stage. The photographed Lake Worth animals provide direct local evidence of egg-laying. One November observation cannot define a Florida-wide breeding season, and neither a dense gathering nor a stranded animal should automatically be described as breeding behavior.

Identification and observation

Photograph the whole animal, the head tentacles and the texture of the body without lifting it. The shaggy projections help separate this animal from the smoother spotted sea hare already included in this guide. Older sources sometimes use Bursatella leachii pleii; the World Register of Marine Species treats that name under Bursatella leachii, not as an additional species for counting pages.

Leave adults and egg cords where they are. Review current FWC marine-life requirements and the rules of the particular park or dive site before considering any collection. This identification page offers no harvest authorization.

References

• Australian Museum: Fort Pierce field report
• Australian Museum: Lake Worth adults laying eggs
• Australian Museum: Boca Raton animals and eggs
• Biscayne National Park mollusk inventory
• OPK: morphology, food and larval development
• WoRMS: accepted name and pleii synonym
• FWC marine-life rules

Collection and habitat protection

Check current FWC marine-life requirements and exact-site restrictions before collecting. This profile is for observation, not collection authorization. Current FWC marine-life guidance. Guidance reviewed November 12, 2026. No location-specific collection clearance is given.

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