Bumblebee Shrimp

Geographical Origin and Habitat: Gnathophyllum americanum has a wide circumtropical distribution. It is commonly found throughout the tropical waters of the Indo-Pacific (from the Red Sea to French Polynesia), the Caribbean Sea, and the western Atlantic Ocean. It inhabits shallow coastal coral reefs, seagrass beds, and rocky rubble zones, living tucked inside crevices and under live rock overhangs, typically at depths shallower than 20 meters.

Taxonomy: Belonging to the class Malacostraca, order Decapoda, and family Gnathophyllidae (bumblebee shrimps). It features a plump, short, and laterally compressed body shape with relatively short but strong claws and fine antennae. Its maximum adult size is extremely small, typically ranging between 1.0 and 2.0 centimeters in total length.

Social Behavior: A predominantly nocturnal, shy, and highly cryptic invertebrate. During the day, it stays hidden deep within rock crevices or coral branches. It shows no aggression toward fish or other peaceful invertebrates in the tank, except for echinoderms. It can be successfully kept in small groups or pairs in the same aquarium.

Coloration and Sexual Dimorphism: The color pattern is striking and serves as camouflage, featuring dense alternating transverse bands of black or dark brown and white-yellowish stripes, resembling a bumblebee or wasp. The tips of the legs and claws may have blue or orange accents. Sexual dimorphism is subtle, with mature females being slightly larger than males.

Tank Setup: Can be housed in small nano-reef aquariums starting from 40-50 liters (approx. 10-15 gallons). The tank must be arranged with plenty of live rock to provide small crevices and caves where the shrimp can hide during the day. It does not require special lighting or strong water movement, as long as conditions remain stable.

Diet and Feeding: A specialized predator of echinoderms. In the wild, it feeds on the tube feet and tissues of starfish and sea urchins. In captivity, to keep it healthy long-term, it must be offered starfish (such as Asterina pests or pieces of frozen starfish). While it may occasionally accept small pieces of shrimp meat or frozen food, it cannot survive without echinoderm tissue.

Water Quality: Demands stable marine parameters: water temperature between 23°C and 27°C, pH between 8.1 and 8.4, specific gravity between 1.023 and 1.025, and KH between 8 and 12 dKH. It is extremely sensitive to copper treatments and high levels of nitrates/phosphates. Sudden salinity changes can cause failed molting of their exoskeleton.

Compatibility and Tankmates: Reef-safe with corals, but a lethal threat to ornamental starfish (such as Linckia or Fromia species) and small sea urchins. It cohabitates well with small, peaceful fish like gobies, pipefish, and clownfish. Avoid large predatory fish like wrasses, hawkfish, or groupers that will easily eat it.

Aquarium Breeding: Breeding in home aquariums is extremely difficult. The female carries the eggs under her abdomen until they hatch. The released larvae are planktonic and go through several delicate larval stages before molts. They require specialized live foods such as rotifers and microalgae cultures to survive.

Risks and Diseases: The primary risk is starvation if not supplied with starfish to feed upon. Another danger is a failed molt due to iodine deficiency or fluctuating salinity. Being an invertebrate, it is highly sensitive to copper-based medications or formalin treatments used to treat marine fish diseases.