AquaNexus knowledge library
Original practical guides connected to the Aquatic Life Database.
Many small bristle worms in reef aquariums are scavenging polychaetes that consume leftover organic material, but “bristle worm” is a broad label and some fireworms can sting people or damage livestock; identify behaviour and body features before removing every worm.
Freshwater copepods are a diverse group of small crustaceans; many are free-living members of the food web, but some copepod relatives are parasitic, so attachment to fish changes the diagnosis.
Scuds are freshwater amphipod crustaceans that commonly graze detritus and biofilm, but a dense population can compete for food and some amphipods may interact with vulnerable animals, so shrimp and fry tanks need observation rather than a blanket “safe” label.
Seed shrimp are tiny bivalved crustaceans called ostracods; many aquarium populations graze biofilm, microbes and detritus and are better managed by controlling food than by blanket treatment.
Control Aiptasia deliberately and locally: confirm the anemone, choose a method suitable for the infestation and reef inhabitants, and avoid rough scraping or fragmentation that can leave tissue behind and create additional colonies.
Quarantine aquarium plants in a separate, observable system before they enter established tanks; inspect repeatedly, remove visible hitchhikers and use only plant- and livestock-compatible treatments rather than assuming one dip eliminates every pest, egg or pathogen.
Reduce risk to small livestock while protecting snails, shrimp and biological filtration.
Use shape, movement, location and damage patterns before reaching for chemicals.
Decide whether a new worm, crab, snail, anemone or slug is useful, harmless or dangerous.
Use light, nutrients, flow, grazing and maintenance history to find the cause.
Tiny cap-shaped animals that cling to aquarium glass are often freshwater limpets—small gastropod molluscs that graze surface growth; excess numbers are usually managed by reducing available food and preventing transfers, not by blanket molluscicide use.
Tiny white worms on the glass or substrate are often free-living detritus-associated worms, but attachment to fish, lesions or unusual body shapes require a different response.
A large aquatic insect larva with six legs and an extendable grasping mouthpart may be a dragonfly or damselfly nymph; both are predators and should be removed from aquariums containing small fish, shrimp or fry.
Confirm that the organism is actually a leech, isolate affected livestock and remove visible leeches carefully; leeches attached to fish can feed on body fluids and may contribute to injury or disease transmission.
