includes shrimp, lobsters, hermit crabs, emerald crabs, decorator crabs and sally lightfoot crabs
Marine crustaceans are best known for their joined outer shell. Many shed or molt their hard exoskeleton as they grow. Crustaceans, such as crabs, shrimp and lobster, can be vivid in color and fast-moving.
Marine Crustacean Facts
Average Adult Size
2 to 12+ inches long, depending on species
Average Life Span
depends on species
omnivore and herbivore, depending on species
Minimum Aquarium Size
29 to 50 gallons, depending on species
A well-balanced marine crustacean diet consists of:
Frozen brine or mysis shrimp.
Usually feeds off excessive food or debris in the tank.
Certain species are herbivores and eat algae.
Things to remember when feeding your marine crustacean:
Feed 2 to 3 times a day.
Thaw frozen food before feeding.
Keep in an appropriately sized aquarium; provide hiding places or caves, appropriate depth of substrate based on species and plenty of décor for marine crustaceans to protect themselves.
Use of copper-based medications is toxic to crustaceans.
The use of an iodine supplement can be beneficial during a crustacean's molting process.
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.
Small crabs and shrimp make excellent first crustaceans.
Some crustaceans are known to eat small fish and invertebrates.
May become aggressive toward some species in smaller aquariums.
Many species provide great natural algae and parasite control.
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.
Marine crustaceans are usually not compatible with mollusks, squid and octopuses. Caution should be used when adding crustaceans to a tank that contains slow-moving aquatic life or aquatic life known to eat crustaceans.
Signs of a Healthy Crustacean
Sleek, non-pitted shell and legs (applicable to certain species)
Avoid overcrowded conditions, which are a major cause of stress and disease. Maintain good water quality with regular water changes and adequate filtration.
loss of color or appetite
spots or fungus on body
Missing limbs or antennae
Common Health Issues
Symptoms or Causes
Health Issue Body or surface erosion
Symptoms or Causes Poor water quality; nutrient deficiency.
Suggested Action Test and treat water immediately; maintain proper diet.
Health Issue Loss of appendage or antennae
Symptoms or Causes Fighting between crustaceans or due to an aggressive fish.
Suggested Action Will usually regenerate. An iodine supplement can help with the molting process.
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 cdc.gov/healthypets 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.
Free Standard Shipping automatically applies to your qualifying minimum online purchase subtotal of $49. No promotion code necessary. Subtotal refers to amount of order before taxes and shipping. All Free Shipping is based on Standard Shipping rates. P.O. Boxes, Alaska/Hawaii are based on USPS Priority Mail.
Free Shipping Exclusions: Cat litter, dog litter, ice melter, wild bird food, live fish & rock, aquatic gravel and accents; crickets, live food and frozen food; out-of-stock items, Donations, Petco or Unleashed by Petco Gift Cards and eGift Cards; items shipped through white glove delivery or LTL delivery; orders exceeding the maximum weight limit of 300 lbs.; and applicable taxes. Additional exclusions may apply and will be noted on the Product Detail page and/or Shopping Cart.
Cat litter, dog litter, wild bird food, live & frozen food and oversized items may incur an additional per-item shipping & handling fee or surcharge. Additional fees may apply and will be noted on the Product Detail page and/or Shopping Cart.
Did you know? Repeat Delivery orders always ship free. Learn More
20% off your first Repeat Delivery order Terms & Conditions
- The 20% discount is valid only on first-time Repeat Delivery orders.
- Enter promo code: rdsave20 in your Shopping Cart. The Promotion Code is one time use only.
- The 20% discount automatically applies to your first-time, qualifying Repeat Delivery purchase subtotal. Subtotal refers to amount of order before taxes and shipping. Maximum discount amount is $20.
- Exclusions: Add-on items, out-of-stock items, Donations, Petco Gift Cards and eGift Cards; items shipped through white glove delivery or LTL delivery; orders exceeding the maximum weight limit of 300 lbs.; and applicable taxes. Additional exclusions may apply and will be noted on the Product Detail page and/or Shopping Cart.
- Petco.com charges applicable tax on all orders shipped to states in which Petco has a physical location.
- Promotion Code valid for one use per order.
- Promotion Code cannot be redistributed or used in combination with any other offer.
- Petco.com in its sole discretion may refuse to redeem any Promotion Code that it believes in good faith to be fraudulently or improperly obtained.