Rough fileclam

Geographical Origin and Habitat: Lima scabra, commonly known as the rough fileclam or electric flame scallop, is native to the warm tropical waters of the Western Atlantic Ocean, widely distributed throughout the Caribbean Sea, the Gulf of Mexico, Florida, and the Bahamas. It inhabits shallow coral reefs at depths of 1 to 20 meters, typically settling in dark crevices, underneath coral overhangs, or inside shaded caves where it anchors itself securely to the rocky substrate using strong byssal threads.

Taxonomy: It belongs to the class Bivalvia, order Limida, and family Limidae. It is a filter-feeding bivalve. Previously placed under the genus Lima, it is also referred to as Ctenoides scaber in scientific literature. No subspecies are recognized. It is famous for a bright flashing line of light along its mantle edge, which is not bioluminescence but rather the result of ambient light reflecting off a highly reflective band of silica tissue.

Social Behavior: While it is a sessile animal, it retains the ability to move if threatened or if local water flow is inadequate. It can swim short distances by rapidly clapping its valves together, expelling water to propel itself forward. It exhibits no social behavior and is completely solitary, though it often hosts small commensal cleaning shrimp within its rock shelter.

Coloration and Sexual Dimorphism: The shell is oval, light brown to white, with rough radial ribs. The internal mantle is a bright fiery red or orange due to carotenoid pigments obtained from its diet. Numerous long, slender red or white tentacles extend from the mantle edges. There is no visible sexual dimorphism, and males and females are externally indistinguishable.

Tank Setup: Requires a mature marine aquarium of at least 100 liters (25 gallons). It must be placed in a shaded area or beneath rock overhangs, as it avoids direct, high-intensity lighting. The rockwork must be stable and provide tight crevices. Water movement should be moderate to strong to ensure food particles are carried directly to the clam's tentacles.

Diet and Feeding: It is a pure filter feeder and is extremely difficult to keep alive long-term without dedicated target feeding. It must be fed daily with live or concentrated phytoplankton, zooplankton, and liquid foods designed for filter feeders. Use a target-feeding pipette to gently disperse food near the clam with the water pumps temporarily turned off.

Water Quality: Demands pristine, stable marine water parameters. Maintain water temperature between 22°C and 26°C (72-79°F), pH between 8.1 and 8.4, specific gravity between 1.023 and 1.025, and KH between 8 and 12. Adequate calcium (400-450 ppm) and magnesium (1250-1350 ppm) levels are critical for maintaining its calcareous shell.

Compatibility and Tankmates: 100% reef-safe and harmless to fish and corals. However, it is highly vulnerable to predation. Do not house with mollusk-eating fish (such as triggerfish, pufferfish, and large wrasses) or opportunistic crabs and predatory shrimp that will pinch its tentacles or pry open the shell.

Aquarium Breeding: Breeding in home aquaria is virtually impossible. They reproduce by releasing gametes into the water column, where fertilization occurs externally. The resulting free-swimming planktonic larvae are delicate and are quickly removed by mechanical filtration and protein skimmers.

Risks and Diseases: The primary risk is starvation, which typically occurs within a few months if adequate plankton is not supplied. A dead clam can quickly foul the water quality; if the shell remains open and the tentacles do not retract when touched, remove the animal immediately. Extremely sensitive to copper treatments.