Fish identification archive / Yellowfin Mojarra

Yellowfin Mojarra

Gerres cinereus

Fun facts for your next surface interval

A tiny-toothed surprise: Its apparently toothless mouth actually contains tiny brush-like teeth.
Pop-out dining: The feeding mouth can extend and point downward.
Fins that pack away: The dorsal and anal fins fold into scaly sheaths.

Florida and local context

Palm Beach County / Lake Worth Lagoon: Florida Museum places an x in the Verified column for this exact scientific identity in its Lake Worth Lagoon list. This is a regional record, not a count, frequency estimate or guaranteed sighting.

Documented regional presence is not a guarantee of an encounter or a measure of how common this animal is at your dive site.

How to recognize this animal

Yellowfin mojarra have a moderately deep silvery body and about seven or eight faint dark bars. The pelvic and anal fins are yellow. A highly extendable mouth points downward when protruded, and the lower outline of the head is noticeably concave. A long pointed pectoral fin and deeply forked tail complete the identification package.

Size and life stages

The maximum reported size is about 41 centimeters, roughly 16 inches. Large, conspicuous scales cover much of the head and body, but forehead scales do not extend forward of the eye. The front dorsal spines are elevated without the extremely long spine seen in some other mojarras. Bright reflected light may wash out the faint bars in photographs.

Habitat and where to look

Sand near reefs is characteristic habitat, and the species also enters brackish estuaries. Smithsonian lists a roughly 0–30 meter depth interval, flagged with uncertainty in the narrative. A mojarra over open sand should therefore be interpreted in its estuarine or reef-edge setting rather than assumed to be a fish that lives only on coral.

Range and local context

The species is distributed in the western Atlantic from Bermuda to Brazil, with both marine and estuarine habitat use. Florida Museum explicitly marks its Lake Worth Lagoon record as verified, supporting Palm Beach County occurrence. This does not measure present abundance or guarantee an encounter at a particular dive site.

What is on the menu?

Recorded foods include small crustaceans, mollusks, worms and other benthic animals. Although the jaws can appear toothless, they carry tiny brush-like teeth. The protrusible mouth allows the fish to direct feeding downward. A diver can watch natural mouth movement without disturbing the substrate or supplying food, and should avoid claiming the exact prey from a brief head-down posture.

Daily habits and behavior

The dorsal and anal fins can fold into scaly sheaths along their bases. A fish with folded fins may look different from one shown in a guide with fins spread. The long pectoral commonly extends beyond the anal-fin origin. A sequence of side photographs during ordinary swimming can reveal these characters more reliably than a single strongly angled image.

Mating and the next generation

The species database records pelagic eggs and pelagic larvae. Its early life therefore includes a water-column stage despite the adult association with sand and bottom feeding. No species-specific Palm Beach breeding calendar was verified here. The yellow fins are an identification character, not reliable evidence of sex, spawning condition or a seasonal breeding display.

Look-alikes and identification traps

Silver jenny and other Eucinostomus mojarras may look very similar when small or poorly lit. Compare body depth, forehead scaling, dorsal-spine proportions and the yellow pelvic and anal fins. Porgies usually have a different head-and-mouth arrangement and do not share the same highly protrusible feeding mouth. A faintly barred silver fish is not enough for a confident species record.

Observe without disturbing

Keep a little distance over sand so your fins do not create a sediment cloud or change the feeding scene. Do not bait, dig or herd the fish against structure. Include the head and both lower yellow fins in photographs when possible. Record an uncertain small mojarra as such rather than applying the name or fishing rules of silver jenny to it.

Harvest, protection and eating safety

Harvest conditional; food safety unverified

Florida state waters: the general recreational limits apply, with no species-specific statewide size limit or annual closed months identified. Check federal and local rules separately. No species-specific positive eating-safety recommendation is established by this overlay; consult current DOH advice and do not substitute guidance for a similarly named fish.

This color is a qualified summary, not permission to collect or a guarantee that a particular catch is safe to eat. Read the current rules and health guidance below.

Recreational harvest is conditional; species, area, gear and food-safety checks required

Can it be hunted or harvested?

In Florida Atlantic and Gulf state waters, this species falls under the general recreational rules unless an area-specific rule below is stricter. The default daily bag is two fish or 100 pounds per person, whichever is greater, not unlimited harvest. No species-specific statewide size limit is listed for this category. The cited default is a daily bag, not an additional off-water possession allowance. A saltwater fishing license is required unless exempt, including for Florida landings from federal waters; a shoreline-only license does not cover taking fish while swimming or diving. Legal general gear includes hook and line, spears, gigs, haul seines and cast nets subject to location restrictions. Recreational rules do not authorize commercial sale.

Florida seasons and areas

No species-specific annual closed months are listed in the cited Florida general category. This is not a blanket year-round permission: state rules do not by themselves establish the rules for every Gulf or South Atlantic federal trip. Confirm the federal management area and any protected-zone conditions before taking or landing fish. The designated Western Dry Rocks area closes to all fishing April 1–July 31. In Biscayne National Park, the designated bonefish pre-spawning area closes to fishing and fish possession March 1–May 31; continuous transit with fish and gear properly stowed is allowed. Sanctuary, park and refuge zones may impose additional no-take or gear restrictions. These are area rules, not a claim that every Florida site is closed.

Can it be speared?

Spearing is allowed for this species only where the location and other rules permit it. No powerheads, bangsticks or rebreathers. No spearfishing in freshwater; within 100 yards of public swimming beaches, commercial/public fishing piers or bridges open to public fishing; or within 100 feet of an above-water jetty except the last 500 yards of a jetty longer than 1,500 yards from shore. It is prohibited from Long Key north to the Miami-Dade line in Monroe County, in state-park waters and in Volusia inland waters for this species. Check additional federal protected-area rules.

Is it safe to eat?

This identification page cannot establish that a particular catch is safe to eat. Consult current Florida DOH advice for the exact species and capture water, especially for pregnancy, breastfeeding and children. Do not borrow an advisory for a similarly named fish. Prompt chilling and proper cooking reduce some hazards, but cooking does not remove mercury or all marine toxins; absence of a named advisory is not a safety clearance.

Before you act: This recreational overview is not permission to collect or spear at your dive site. Confirm the species, date, management area, state or federal waters, gear, licenses and current local closures. Identification artwork cannot establish an identification or guarantee seafood safety.

Official rules and health guidance

Reviewed 2026-11-10. Rules and advisories can change; check the linked authorities before harvesting or eating.

Sources and review

Reviewed 2026-11-10.

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