Pachypanchax sakaramyi

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Pachypanchax sakaramyi
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Pachypanchax sakaramyi

Systematics
Superordinate : Earfish relatives (Atherinomorphae)
Order : Toothpies (Cyprinodontiformes)
Subordination : Aplocheiloidei
Family : Aplocheilidae
Genre : Pachypanchax
Type : Pachypanchax sakaramyi
Scientific name
Pachypanchax sakaramyi
( Holly , 1928)

Pachypanchax sakaramyi is an endangered fish in Madagascar . It is named after the Sakaramy River , the river in which the type specimens were caught.

distribution and habitat

The freshwater fish inhabit rivers with high currents and the tributaries of deeper crater lakes of the Ambohitra massif in northern Madagascar. Specimens of all sizes can be found in both fast-flowing and quiet areas, but the greater number of individuals is found in the latter. The native waters of P. sakaramyi are clear and slightly alkaline with a pH of 7.2 to 7.5. They carry only a small amount of dissolved salts and are therefore relatively soft with two to four degrees of German hardness and have a very low conductance of around 58 to 75 μS / cm².

Appearance

In terms of habit , P. sakaramyi corresponds to the typical appearance of the genus Pachypanchax . It reaches a total length of eight centimeters. There occur green and red shapes, the far back standing dorsal fin starts on the tenth and eleventh ray of the anal fin . These two fins are colored light brown and each has a smoky gray ribbon. The pectoral fins are colorless and transparent. Except for a beige base, the pelvic fins are also transparent. The caudal fin has a pattern of light brown spots. Pachypanchax sakaramyi differs only slightly from Pachypanchax omalonotus , the Madagascar pike previously discussed as a subspecies . The two species can also be crossed without restriction.

Way of life

P. sakaramyi feeds mainly on approach food and small aquatic invertebrates. Since he had not originally share its habitat with other species of fish, its only natural predators of the Malagasy Kingfisher ( Alcedo vintsioides ), predatory insect larvae and macrobrachium ( Macrobrachium ). Young specimens up to a dozen animals live in shallow water near the shore in loose associations. When they reach fertility, they often seek deeper water away from the shore. In adulthood, P. sakaramyi lives solitary. Females tend to move slowly and make frequent stops, the males are in constant motion. Although no territorial behavior can be observed, the fin injuries of wild-caught males indicate occasional, violent arguments. The spawning season is either not seasonally limited or extremely lengthy from the beginning of spring to autumn. The pairing, performed with the usual rituals, takes place on branches that have been washed over or between large stones on the bottom of the water and can be repeated several times in quick succession.

status

P. sakaramyi has disappeared from most of its original habitat . One of the causes is the deforestation of the Ambohitra massif and its negative impact on the local water balance. Small bodies of water that used to exist constantly no longer carry water all year round. Another serious problem is the feeding pressure exerted on the fry of P. sakaramyi by introduced fish species such as guppies ( Poecilia reticulata ) and a representative of the gambus , Gambusia holbrooki . A large part of the original habitat has been lost since the Sakaramy spring was opened up in 2000 for drinking water for several private houses and the guest house of a Benedictine monastery. The IUCN therefore lists P. sakaramyi as critically endangered (“threatened with extinction”).

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