Resource Center Menu


includes tridanca clams, flame scallops, nerite snails, turbo snails, astrea snails, cerith snails, bumble bee snails and conch

Clams are bivalves whose bodies are enclosed in two shells. Some live on top of the substrate, though many burrow into it. Flame scallops are found in many marine settings; recommended for experienced marine aquarists. Marine snails aid in removing algae and detritus from the aquarium.


Mollusk Facts

Average Adult Size depends on species
Average Life Span depends on species
Diet depends on species
Minimum Aquarium Size 29+ gallons, depending on species
Water Temperature: 72-78°F
Specific Gravity: 1.023-1.025


A well-balanced mollusk diet consists of:

  • Clams - Filter feeders that feed on live or preserved phytoplankton, or special liquid food; photosynthetic vitamins or trace supplements may also be given. Many species of clam require moderate to intense lighting to thrive as they contain the symbiotic algae called zooxanthellae and receive the majority of their nutrition from the light through photosynthesis.
  • Snails - Usually feed off algae and detritus (decayed matter) in the aquarium; calcium supplement must also be given.
  • Flame scallops - Feed on live, floating microplankton; supplements of phytoplankton and liquid foods needed.


Things to remember when feeding your mollusk:

  • Clams - Smaller clams should be fed several times a week; larger do not need supplemental feeding.
  • Snails - Supplement with dry seaweed if insufficient algae is present.
  • Flame scallops - Feed supplements to each scallop individually by dispensing food just upstream with a pipette or straw.


  • Keep in an appropriately sized aquarium; full spectrum lighting and proper filtration are essential.
  • Use of copper-based medications is toxic to mollusks.
  • Stable water quality and parameters are critical to the health of aquatic life. If you are unsure of your water quality, Petco provides free water testing.

Normal Behavior

  • Some clam species prefer to attach to a solid surface, while others prefer to sit in the substrate.
  • Mollusks are sensitive to high levels of nitrate and snails need a lot of room to graze.
  • Flame scallops can be kept singly or with other bivalves; peaceful filter feeder.

Habitat Maintenance

  • Daily: check filter, water temperature, specific gravity and other equipment.
  • Weekly check water quality at least once a week.
  • Monthly: change 10 to 25% of the total volume of water every 2 to 4 weeks, or as needed.
  • Introduce new inhabitants to the aquarium gradually.


  • Check Petco saltwater compatibility Care Sheet for more information about your mollusk.


Signs of a Healthy Mollusk

  • Clam shell closes quickly when bothered; fully opened throughout most of the day.
  • Flame scallop mantle should be expanded and breathing siphons extended; shell closes quickly when bothered.
  • Snails are usually attached to the glass, décor or substrate.
  • Remains upright and the operculum is open and intact.
  • Avoid overcrowded conditions, which are a major cause of stress and disease. Maintain good water quality with regular water changes and adequate filtration.

Red Flags

  • Clam is closed for long periods of time; tissue decay
  • Flame scallop mantle falls inward, away from shell; shell fails to close quickly when bothered
  • Snail is upside down with operculum closed or upside down with foot extended

Common Health Issues

Health Issue Symptoms or Causes Suggested Action
Health Issue Little is known about diseases that affect mollusks; as long as environmental conditions and food supplies are adequate, mollusks are fairly resistant to disease. Symptoms or Causes   Suggested Action  


Ask a store partner about Petco's selection of books on marine crustaceans and the variety of private brand products available for the care and happiness of your new pet. All private brand products carry a 100% money-back guarantee.

Because all aquatic life are potential carriers of infectious diseases, such as Atypical Mycobacterium and Salmonella, always wash your hands before and after handling your aquatic life or habitat contents to help prevent the potential spread of disease.

Pregnant women, children under the age of 5, senior citizens and people with weakened immune systems should contact their physician before purchasing or caring for aquatic life and should consider not having aquatic life as a pet.

Go to the Centers for Disease Control at for more information about aquatic life and disease.

This care sheet can cover the needs of other species.

Note: The information on this Care Sheet is not a substitute for veterinary care. If you need additional information, please refer to the sources on the following page or contact your veterinarian as appropriate.

Developed with and approved by a qualified veterinarian.