Fish identification archive / Cadlina rumia

Cadlina rumia

Cadlina rumia

Fun facts for your next surface interval

The yellow marks include mantle glands. [source]
Laboratory animals responded to waterborne chemical cues. [source]
The local photo was taken near Peanut Island. [source]

Florida and local context

The JaxShells species page identifies Cadlina rumia in a credited photograph and expressly locates the photographed animal at Lake Worth Lagoon near Peanut Island, Palm Beach Inlet, Palm Beach County, Florida. This supports only the named historical record.

A documented past record does not establish present abundance or guarantee an encounter.

Sources: JaxShells: credited named-site photograph and caption

How to recognize this animal

A flattened, pale oval nudibranch with tiny bumps and yellow mantle glands. Head tentacles and gills may be yellow-brown. A close view of these features is more useful than calling any small white dorid this species.

Sources: Primary research: species treatment and observations

Size and life stages

The primary Caribbean guide reports up to 15 mm. That is the guide’s reported value, not a measured limit for the local population. A Florida life-stage series is not available in the reviewed evidence.

Sources: Primary research: species treatment and observations

Habitat and where to look

The credited photograph is from Lake Worth Lagoon near Peanut Island, Palm Beach Inlet, Palm Beach County, Florida. A measured local depth is not supplied in the caption used here. This is a documented observation setting, not the species’ complete habitat or depth range. Do not relabel a Peanut Island vicinity record as Blue Heron Bridge unless the source says so.

Sources: JaxShells: credited named-site photograph and caption

Range and local context

The corridor evidence here is restricted to the named locality in the photograph caption. A historical record is not proof of present abundance, a continuous Vero Beach–Key Largo distribution or a guaranteed sighting.

Sources: JaxShells: credited named-site photograph and caption

Feeding and diet

Species-specific experiments used Dysidea etheria as prey. Other primary observations document several sponge foods; do not assume that every sponge beside a local animal is being eaten.

Sources: Primary research: species treatment and observations

Daily habits and behavior

In controlled two-current laboratory trials, animals approached water carrying sponge or same-species cues and avoided water with cues from a potential crab predator. This supports chemical discrimination under the tested conditions, not a measured navigation distance in Florida.

Sources: Primary research: species treatment and observations

Mating and the next generation

Species-specific reproductive details remain limited in the reviewed evidence. No Florida spawning season, egg identification, maturity size or larval schedule is claimed. An egg mass near an animal does not alone establish parentage.

Look-alikes and identification traps

Small pale dorids can be difficult to distinguish in a single photograph. The reviewed sources do not provide a complete local comparison key; document mantle glands, gills and head tentacles together.

Sources: Primary research: species treatment and observations

Observe without disturbing

Use careful buoyancy and photograph the animal where it is. Do not touch, feed, chase, move, turn over its shelter or pull apart its algae or sponge. Leave eggs and attached organisms undisturbed. This observation guidance is not a conservation-status assessment or permission to collect; consult the separate scoped legal review and exact site restrictions before any collection.

Live collection only; site restrictions

Cadlina rumia is reviewed as a nudibranch in Cadlinidae, matching FWC's explicitly listed nudibranch/sea-slug marine-life group. Yellow means live collection subject to limits and site restrictions, not food harvest.

This scoped status is not permission to collect or a guarantee of food safety.

Harvest, collection and food status

Checked 2026-11-11.

Harvest status

Live collection only; site restrictions. Cadlina rumia is reviewed as a nudibranch in Cadlinidae, matching FWC's explicitly listed nudibranch/sea-slug marine-life group. Yellow means live collection subject to limits and site restrictions, not food harvest. For covered marine-life organisms, FWC requires live landing and continued live maintenance with an adequately sized circulating, aerated or oxygenated system, and a recreational saltwater license unless exempt. Limits are 20 organisms combined per person per day, at most five of one species; two-day possession is 40 combined, at most ten of one species. Use authorized collection gear. Recreational sales are prohibited. FWC states its marine-life rules also apply in federal waters. These requirements do not authorize killing for food.

Season and jurisdiction

Vero Beach–Key Largo Atlantic corridor; recreational collection only. Exact state/federal jurisdiction, park and sanctuary boundaries, method, possession, landing and trip date must be checked. This is not trip clearance. The reviewed FWC recreational marine-life summary specifies no scheduled annual closure for this nudibranch group. This is not a year-round collection guarantee and does not override permanent, temporary or seasonal area closures.

Closed areas and possession

The mapped Blue Heron Bridge dive site is closed to marine-life harvest; do not relabel every Peanut Island record as inside that boundary. Biscayne National Park prohibits ornamental collection without a superintendent collecting permit. Florida State Parks require express permission for animal collection; an ordinary fishing allowance at John Pennekamp is not clearance to collect sea slugs. In Key Largo Management Area, taking or injuring marine invertebrates is prohibited: the lobster/crab exceptions do not cover these mollusks. Sanctuary Preservation Areas, Ecological Reserves and research-only areas restrict taking and possession; lawful transit exceptions require their exact conditions. Overlapping zones apply together. Check mapped boundaries and posted restrictions before entry.

Collection method

Live-collection rules are not permission to spear or kill an animal. Key Largo Management Area independently prohibits spearfishing and carrying spearfishing equipment except specified uninterrupted transit or law-enforcement circumstances. Collection and possession restrictions can apply even when no spear is used.

Food and menu status

Not offered here as a food-harvest species. Exact-species food suitability and a dated local restaurant menu have not been verified. This is not a claim of proven toxicity, universal inedibility, or absence from every menu. Recipes are disabled; menu status is unknown.

Official sources

Identification and source cautions

This is a source-identified photograph, not independent anatomical or molecular reidentification.
Historical occurrence does not establish present abundance or guarantee a sighting.
Use only the stated locality; Peanut Island records must not automatically be relabelled as Blue Heron Bridge.
Photographs remain copyrighted; no reuse permission is implied.
Source photographs are copyrighted reference material and are not reproduced in this draft.

Sources and review

Biological claims and depicted anatomy independently reviewed on 2026-11-11; publication and public-render verification remain pending. Photographs on cited sites are reference material and are not reproduced here.

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