Pachypanchax varatraza

Pachypanchax varatraza – Loiselle, 2006

Varatraza Killifish / Zono

Mahazava Creek at Mahazava village (13° 52’ 97”S - 49°56’22”E), 30 meters above sea level in the Ampanobe River drainage.

PACHY-pan-chax vaar-ah-TRA-za

Named after the Malagasy word for the east wind.   Acknowledges the unanticipated presence of a Pachypanchax on eastern slope of the Tsarantanana Massif.

3.14 inches (8.0 cm) wild collections

 Species has the shortest pectoral fins of all Malagasy Pachypanchax.  Differs from P. sakaramyi and P. sparksorum in size, P. varatraza is smaller, and lack of pectoral scales. 

Lack of discrete metallic gold spangling on flanks and rounded dorsal and anal fins in males distinguishes this species from P. omalonotus. Absence of iridescent white edging to the vertical fins or lack of darker submarginal banding on vertical fins distinguishes P. varatraza from all other Malagasy species.

Males of this species display polymorphism in colour.  Males display a red colour morph and a green colour morph. 

Loiselle (2006) notes that all green morph individuals display rusty-brown to maroon edging on scales of the posterior half of the body but its extent and intensity differ between populations. 

The green morph males found in the Ampanobe River basin display redder unpaired fins and a more intense maroon edging on their scales.

A review of the Malagasy Pachypanchax (Teleostei: Cyprinodontiformes, Aplocheilidae), with descriptions of four new species.
In: Zootaxa 1366: 1 – 44 (2006)

None known

Mahazava Creek

Amdampy Creek

Antafiabe Creek

The Blotched Snakehead (Channa maculate) appears to have caused the extirpation of P. varatraza from the lower reaches of the Menambery, Fanambana and Ampanobe rivers.  Deforestation of the Menambery headwaters has reduced viable habitat in this area to a short, high-gradient tributary. 

The Fanambana and Ampanobe rivers both provide habitat for this species although Gambusia holbrooki (Eastern Mosquitofish) is present in the latter water course.  Loiselle classifies Pachypanchax varatraza as a species of special concern based on WCU criteria (Loiselle, 2006).  This status recommends constant monitoring of populations for conservation purposes.

Substrates range from bare bedrock, clay/sand bottoms and mixes of sand/gravel.  Marsilea sp. was found in the shallows of Andampy Creek.  No other aquatic macrophytes were observed at other collection locales (Loiselle, 2006). 

Pachypanchax species generally need forested stretches of river to survive.

pH: 6.5

Conductivity: 49 µS

General Hardness: < 18.0ppm

Carbonate Hardness: 36.0ppm

Gabusia holbrooki

Oreochromis mossambicus

Awaous sp.

Glossogobius giuris

North American populations stem from a collection by P.V. Loiselle in 2000 from Mahazava Creek.  Breeding populations existed at the New York Aquarium and at the Denver Zoo; most captive specimens originated from one of these institutions. 

To my knowledge only the red morph has been brought into captivity.

Males compete for access to females and fatalities to both sexes do occur due to aggression.  Pachypanchax varatraza is one of the least aggressive Malagasy killifish in captivity.

Spawning in trios, or 2:5 rations can be accomplished in 10 gallon tanks.  Increased success has been had in larger enclosures.

In the wild:

In captivity:

Specimens do not appear overly prone to water chemistry or water quality issues

pH: 6.5-7.5

Temperature: 70-75 °F

dKH and dGH: 0-4°

Undergravel filter with frequent water changes of 20-30% is sufficient for breeding

The author spawns Pachypanchax sp. in trios or 2:5 ratios of males to females.

Yarn mops may be supplied, but successful reproduction has taken place with only gravel substrate available.

Eggs can be allowed to hatch in the adult tank; some fry cannibalism by parents is normal, but with a constantly spawning group this behavior appears to wane with time allowing for the rearing of fry in the adult tank.