Southern hardshell clam

Southern hardshell clam (Mercenaria campechiensis) — field identification starting point: a two-valved bivalve shell; confirm shell outline, ribs, hinge and interior features before harvest.

Most clams in this guide are a few inches across; use shell length/width and any legal minimum for the exact species.

Large bivalves in this group can exceed several inches; exact maximum varies by species.

What it eats isn't well documented yet for this species.

It lives from the tide zone to shallow water in firm sand or sandy mud, sometimes near seagrass and algae, and rarely in the surf. It is dug in shallow water, and recreational clammers find it by feeling with bare feet.

Found in Puerto Rico. Start in the documented habitat and substrate for this species, then narrow the search using depth, current, structure and food activity. Habitat reference:

Habitat: sand bottom, mud bottom, seagrass and intertidal.

From the surface down to 66 ft (20 m).

Search only legal collection areas and depths where the bottom can be inspected safely; closures and sanitary status matter more than a fishing depth number.

Water: marine. Habitat: sand bottom, mud bottom, seagrass and intertidal.

Collect only during open legal/sanitary periods.

Use daylight/visibility and safe tide conditions unless local rules and experience support another approach.

Low water or low current can improve access/visibility, but never enter exposed reef, surf or mudflat conditions unsafely.

Choose sea state, wind and visibility that let you hold position and handle the fish safely. Avoid treating rough weather as a feeding advantage.

Not applicable to hand/collection fisheries.

Not applicable.

Species ID guide, gloves, lawful collection tool/container, measuring device if required, and current area/food-safety rules.

Not applicable; do not invent hook-and-line tackle for a shellfish collection species.

Not applicable.

Not applicable.

Identify the exact species, verify collection area/season/size and sanitary advisories, then use the least damaging legal collection method.

Let it go quickly if you're not keeping it.

Good eating — a common food fish where it's caught. Cook shellfish thoroughly; only eat raw shellfish from approved, tested waters.

Good table fare when bled, iced and cooked fresh.

Safety first: HARVEST-AREA FOOD RISK — shellfish can accumulate harmful algal toxins. Check current harvest-area closures/advisories; cooking may not make marine toxins safe. Only harvest from an open, approved area and after exact species identification. Keep shellfish cold and clean. Scrub shells where applicable; for shucked mollusks, separate edible tissue with clean tools and prevent contact with contaminated seawater or surfaces. Shellfish sanitation closures override any recipe or cleaning advice.

For live clams, mussels and oysters, FDA guidance says to cook until shells open and discard any that stay closed. Cook shucked shellfish until firm and opaque. Only use shellfish from open, approved harvest areas; cooking does not reliably remove every marine biotoxin.

HARVEST-AREA FOOD RISK — shellfish can accumulate harmful algal toxins. Check current harvest-area closures/advisories; cooking may not make marine toxins safe.

No species-specific size, bag or season limits are listed here.

Avoid needless kills and follow protected-species, area and season rules.