Blue Fiddler Crab

The Blue Fiddler Crab (Pertrolesthes sp.) is a peaceful species that is reef-safe with caution, admired for its striking blue coloration, small size, flattened body, and fan-like feeding appendages that make it a fascinating filter feeder.

Males typically may have slightly larger claws and exhibit more territorial posturing, while females/juveniles are generally more reclusive and remain closer to hiding spots or filter feeding areas.

They reach about 1.5 to 2 inches in adult size and should be housed in aquariums of at least 10 gallons.

Provide live rock, hiding spots, and moderate water flow to assist with filter feeding, along with stable water parameters (salinity ~1.020–1.025, temp ~72–79°F, pH ~8.1–8.4), and a secure lid, as they may climb or explore above the waterline.

Diet should consist of suspended plankton, powdered invertebrate foods, finely chopped mysis or brine shrimp, and algae-based foods, and with proper care this "fish" makes a standout addition to the aquarium, especially in nano reef or invertebrate-focused setups.

International Aquatics Quarantine & Guarantee: All fish are checked by marine vets, given a formalin bath, and held for 14 days in copper-treated systems. We feed Selcon-soaked food with Kanaplex and Metroplex during quarantine. Unless marked, all livestock comes with our 15-Day Guarantee. You will receive a video of your fish eating before shipment. On request, we also send photos/videos after arrival at IA. Some species are import-to-order (3-10 business days). Many common species are already cleared or near the end of QT.

Several species will be import-to-order and may take anywhere from 3-10 business days to secure. Once your fish is secured, you will be notified, and the quarantine process will then begin.