Lepidophagy is a specialised feeding

Feeding

Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffix -vore from Latin vorare, meaning 'to devour', or phagy, from Greek φαγειν, meaning 'to eat'.-Evolutionary history:...

 behaviour in fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

 that involves eating of scales

Scale (zoology)

In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...

 of other fish. Lepidophagy is widespread, having been independently evolved in at least five freshwater families and seven marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 families. Lepidophagy has been reported in a range of fish including: Chanda nama (family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Ambassidae

Ambassidae

The Asiatic glassfishes are a family, Ambassidae, of freshwater and marine fishes in the order Perciformes. The species in the family are native to the waters of Asia and Oceania and the Indian and western Pacific Oceans. The family includes eight genera and about fifty species.The family was...

), Terapon jarbua

Terapon jarbua

Terapon jarbua, Target Fish, Crescent Bass, Crescent Perch or Tiger Bass is a Grunter from the Indo-Pacific. It occasionally makes its way into the aquarium trade...

(family Terapontidae

Terapontidae

Grunters or tigerperches are fishes in the family Terapontidae . They are found in shallow coastal waters in the Indian Ocean and western Pacific, where they live in saltwater, brackish and freshwater habitats...

), several marine catfish

Catfish

Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...

 (family Ariidae

Ariidae

The Ariidae or ariid catfish are a family of catfish that mainly live in marine waters with many freshwater and brackish water species. They are found worldwide in tropical to warm temperate zones.-Taxonomy:...

), some piranha

Piranha

A piranha or piraña is a member of family Characidae in order Characiformes, an omnivorous freshwater fish that inhabits South American rivers. In Venezuela, they are called caribes...

, Exodon paradoxus and Roeboides

Roeboides

The genus Roeboides is used to group several species of tetras, including the headstanders, scale-eaters, and crystal tetra. These fish, among other characteristics, are small, are typically transluscent, and have a rhomboid shape.-Species:...

species (family Characidae

Characidae

The Characidae, characids or characins are a family of freshwater subtropical and tropical fish, belonging to the order Characiformes. The name "characins" is the historical one, but scientists today tend to prefer "characids" to reflect their status as a by and large monophyletic group at family...

), along with Perissodus eccentricus

Perissodus eccentricus

Perissodus eccentricus is a species of fish in the Cichlidae family. It is endemic to Zambia. Its natural habitat is freshwater lakes.-Source:* Bigirimana, C. 2005. . Downloaded on 4 August 2007....

, Perissodus microlepis

Perissodus microlepis

Perissodus microlepis is a species of fish in the Cichlidae family. It is found in Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia. Its natural habitat is freshwater lakes. It is a scale-eating 'parasite' on other fish species. It occurs in two distinct morphological forms...

, Plecodus elaviae

Plecodus elaviae

Plecodus elaviae is a species of fish in the Cichlidae family. It is found in Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia. Its natural habitat is freshwater lakes. It forms large schools, and feeds off of the scales of other fish. Being a bi-parental mouthbreeder, both...

, Plecodus multidentatus

Plecodus multidentatus

Plecodus multidentatus is a species of fish in the Cichlidae family. It is found in Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia. Its natural habitat is freshwater lakes.-References:...

, Plecodus paradoxus

Plecodus paradoxus

Plecodus paradoxus is a species of fish in the Cichlidae family. It is found in Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia. Its natural habitats are freshwater lakes and inland deltas.-References:...

and Plecodus straeleni

Plecodus straeleni

Plecodus straeleni is a species of fish in the Cichlidae family. It is found in Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia. Its natural habitat is freshwater lakes. It eats the scales of other fishes.-References:...

(family Cichlidae).

Fish scales are a surprisingly nutritional food source, containing layers of keratin

Keratin

Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...

 and enamel

Tooth enamel

Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...

, as well as a dermal portion and a layer of protein-rich mucus. They are a rich source of calcium phosphate

Calcium phosphate

Calcium phosphate is the name given to a family of minerals containing calcium ions together with orthophosphates , metaphosphates or pyrophosphates and occasionally hydrogen or hydroxide ions ....

. However, the energy expended to make a strike versus the amount of scales consumed per strike puts a limit on the size of the lepidophage; such fish seldom exceed 20 centimetres (7.9 in) and most are under 12 cm (4.7 in). There are a number of advantages to consuming scales: scales are common, covering the body of most fish species, can be regrown relatively quickly by "prey" fish, are abundant and seasonally reliable, and their removal requires specific behaviors or morphological structures.

A diversity of morphologies and attack behaviors are used by lepidophagous predators. The behavioral origins of scale feeding may be different for different lineages.