''Serrasalmus geryi'', the violet line piranha or Gery's piranha, is a species of

fish Fish are aquatic, craniate, gill-bearing 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. Approximately 95% of li ...

found in the lower Tocantins and Araguaia Rivers of

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. This rare ''Serrasalmus'' is the one

piranha A piranha or piraña (, , or ; or , ) is one of a number of freshwater fish in the family Serrasalmidae, or the subfamily Serrasalminae within the tetra family, Characidae in order Characiformes. These fish inhabit South American rivers, ...

of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Serrasalmus ''Serrasalmus'' is a genus of piranhas. They are collectively known as pirambebas; the "typical" piranhas like the piraya piranha are nowadays placed in ''Pygocentrus''. Like all piranhas, ''Serrasalmus'' are native to South America. These fish ...

'' that can coexist with others of the same species (though caution is advised). Gery's Piranha reaches sizes up to 12 inches in length.

Morphology (body characteristics)

Body shape is similar to other compressus group members and are very laterally compressed such as; ''S. altuvei'', ''S. hastatus'', ''S. compressus'' and ''S. altispinis''. The fish is distinctive at all ages with its broad stripe running from lower mouth to top of beginning of

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

. Color: Silvery bodied fish with numerous small spots on the flanks.

Anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

hyaline A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none. Histopathology Hyaline cartilage is ...

with a broad black margin.

Pectoral Pectoral may refer to: * The chest region and anything relating to it. * Pectoral cross, a cross worn on the chest * a decorative, usually jeweled version of a gorget * Pectoral (Ancient Egypt), a type of jewelry worn in ancient Egypt * Pectoralis ...

and

ventral fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s are clear. A

humeral spot Humeral spot (from Latin ''humerus'', pertaining to the shoulder) is a mark or pattern found on several species of fish, typically above the pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding f ...

may be present. Eyes silvery to reddish-orange. A quick visual reference to identify this fish: * Reddish-orange eyes * Violet line running from the lower jaw, over the back until the base of the tail fin * Concave head shape Maximum size: Approx. 25 cm. (10") TL. Specimens over 20 cm. (8") TL are quite rare in captivity. Sexing: Not

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

: males and females look similar.

Care

Tank requirements: Recommended tank size for an adult specimen is 120x45x50 cm. (48x18x20"). Juvenile specimen can be kept in a smaller tank: minimum 60x30x30 cm. (24x12x12"). This is one of the few ''Serrasalmus'' species that have successfully been kept in a group for a while: minimum recommended size to attempt this is 150x50x60 cm. (60x20x24") - only to be attempted by very experienced piranha keepers who know exactly what they are doing, and know what risks are involved. Plants,

driftwood __NOTOC__ Driftwood is wood that has been washed onto a shore or beach of a sea, lake, or river by the action of winds, tides or waves. In some waterfront areas, driftwood is a major nuisance. However, the driftwood provides shelter and fo ...

or rocks provide hiding places; the tank lights should be dimmed. Heavy filtration required to deal with the large amounts of waste this fish produces. A powerhead can be added to provide currents. Fish can be dangerous to hands and other extremities. Care is required in handling. Water temperature: 24-29 degrees

Celsius The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The ...

(76-84 degrees

Fahrenheit The Fahrenheit scale () is a temperature scale based on one proposed in 1724 by the physicist Daniel Gabriel Fahrenheit (1686–1736). It uses the degree Fahrenheit (symbol: °F) as the unit. Several accounts of how he originally defined his ...

). Water chemistry: pH should be between 6.0 - 8.0, ideal is slightly acidic to neutral water: pH 6.5 - 7.2 Soft water is preferred. Compatible species: Although this species has successfully been kept in a group, it is highly recommended to keep the Geryi Piranha as a solitary fish: it remains a

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

and highly aggressive species. Breeding: No instances of captive breeding have been reported yet. Diet: Fish (whole, fillet or feeders *),

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

, cockles,

mussels Mussel () is the common name used for members of several families of bivalve mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,0 ...

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

insects Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...

earthworms An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. Th ...

, pellets. Food items such as

poultry Poultry () are domesticated birds kept by humans for their eggs, their meat or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, quails, a ...

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

meat, and organ meat should be fed sparingly: once or twice a month at most. Meat needs to be unseasoned and trimmed of any fat. On rare occasions this species accepts vegetables, nuts, seeds, or fruit as well. * Live fish need to be quarantined first, so they are safe to feed (containing no diseases or parasites).

Goldfish The goldfish (''Carassius auratus'') is a freshwater fish in the family Cyprinidae of order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the wild have ...

minnows Minnow is the common name for a number of species of small freshwater fish, belonging to several genera of the families Cyprinidae and Leuciscidae. They are also known in Ireland as pinkeens. Smaller fish in the subfamily Leusciscidae are co ...

and other members of the

Cyprinid Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest verte ...

family (Carp-like fish) should be avoided, as these fish contain growth-inhibiting hormones (Thaiminase/Vitamine B1 inhibitors) that could negatively affect the piranha's health and development.

References

"Serrasalmus geryi"
on

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

{{Taxonbar, from=Q148813 Serrasalmidae Piranhas Fish described in 1988