Pinecone Fish

Facts about Pinecone Fish, they are a small group of related species recognized by their unusual armorned scales. Monocentris meozelanicus, Monocentris reedi, Monocentris japonica and Cleidopus gloriamaris are the four species of pinecone fish.

The Pinecone Fish is sometimes called the pineapple fish. The Pinecone Fish species in Japanese waters has been called the Japanese pineapplefish. All Pinecone Fish have been called knight fish, soldier fish, and dick bride-groom fish.
The Pinecone Fish are part of the small Monocentridae family, which contains only four species. There are two genera, Cleidopus and Monocentris. The Pinecone Fish is part of the larger Order Beryciformes, which has 15 families and 143 species.

All Pinecone Fish have distinctive raised scales that resemble the leaves on the outside of a pineapple; the joining of the scutes or hard scales that protect the fish is reminiscent of a pinecone or pineapple. Each scale has a black edge that makes the pattern stand out. Males and females have a similar appearance.
The Monocentris japonica or Japanese pinecone fish ranges from yellow to orange in coloring. Cleidopus gloriamaris has a more rounded, blunted snout compared to the Monocentris japonica.

The compressed, rounded bodies of these Pinecone Fish have plate like scales with prominent ridges. Only the caudal penduncle doesn’t have these scales. These are ray-finned fish. They have four to seven spines on the front dorsal fin. The anal fin is small and rounded. The second dorsal fin is also small, rounded and lacks any spines. The pectoral fins are elongated. The pelvic fin has one large spine it can use to lock itself into place, so a predator cannot pull it out.
Cleidopus gloriamaris is the largest Pinecone Fish at up to twelve inches in length. The Monocentris japonica or Japanese Pinecone Fish ranges from three to six inches in length.
One of the unusual features of these Pinecone Fish species are the orange organs on side of jaw, which is bioluminescent. The bioluminescence isn’t created by the fish but by luminous bacteria that live in a symbiotic relationship with the fish. The bioluminescent patch is thought to attract the zooplankton that the fish eat.

These Pinecone Fish are nocturnal and hide during the day. At night, the Pinecone Fish tend to search for food in the sublittoral zone, the sea floor where sunlight can reach the bottom.
The Pinecone Fish form schools with their own species. Japanese Pinecone Fish actually form predatory schools in deep waters. These Pinecone Fish prefer live brine fish but will eat smaller fish.
Their bioluminescent patches may or may not be used in signaling each other.
These Pinecone Fish are considered peaceful but very hard to maintain.

These Pinecone Fish live on ledges, caves, and rocky shoals in tropical and subtropical waters of the Indo-West Pacific. The Pinecone Fish are found as far north as Japan and as far south as South Africa. The Pinecone Fish can be found around Australia and Pacific islands.
The Pinecone Fish are sometimes found in coral reefs with hard bottoms. They live in depths of 30 to 600 feet, though the juveniles are found in the shallower end of this range.
Those kept in fish tanks need at least 70 gallons of water with temperatures of 64F to 75F and careful feeding. They are sensitive to copper sulfate and medications.

The Pinecone Fish is considered a primitive relative of perches.