About Pinecone Fish

The small pinecone fish family, Monocentridae, contains just four known species, all of which are covered in the chunky spikes that provide the common name. Other striking characteristics include well developed fin spines and bioluminescent -- light emitting -- organs around their mouths.

  1. Species

    • The genus Monocentris contains three typical pinecone fishes, none of which has a specific common name, usually just being called pinecone fish. These are Monocentris japonica, Monocentris neozelanicus and Monocentris reedi, with the first being the most commonly found in the aquarium trade. In a different genus but the same family is the somewhat larger pineapple fish (Cleidopus gloriamari).

    Habitat

    • Pinecone fish inhabit warmer areas of the Pacific Ocean, living around rocky reefs. They tend to remain in the sublittoral zone, where the water is fairly deep but sunlight still penetrates. In the wild, they form shoals -- it has been suggested that they may use their bioluminescent organs to communicate as well as to attract and find food.

    Ecology

    • These fish are nocturnal, resting in caves and crevices during the day and coming out at night to hunt their prey, which consists primarily of zooplankton. In captivity, this means you might not see much of a pineapple fish, as they̵7;ll hide when the tank light is on. Males and females show few, if any, visible differences, and little is known about their breeding behavior. The pinecone fish you see sold for aquariums are almost certainly wild-caught, not captive bred.

    In Captivity

    • They might look appealing, but pinecone fish are not the easiest of marine fish to maintain in a home aquarium and they are not at all suitable for beginners. For starters, they get pretty big. Monocentris japonica reaches a length of 6 inches and pineapple fish, which also sometimes appear for sale, grow to twice that, so they need a large tank -- 100 gallons or more -- with plenty of hiding places in the form of strategically arranged rocks. They need a diet close to what they̵7;d eat in the wild -- in other words, zooplankton and other small live creatures.