Pachypanchax omalonotus

Pachypanchax patriciae – Loiselle, 2006

Patricia's Killifish / Zono

Ampandra River ca. 2km upstream of Ampandra village (13° 24’ 90”S - 48°50’20”E), 44 meters above sea level

PACHY-pan-chax pa-TRISH-ee-ay

Named after Patricia Yazgi; recognizing her support of ongoing efforts to document and conserve the Malagasy freshwater ichthyofauna.

2.05 inches (5.20 cm) wild collections

 Pachypanchax patriciae differs from P. sakaramyi and P. sparksorum in having scales on the chest that are the same size as those on the flanks. Presence of iridescent white edging on the caudal fin of males and a longer caudal peduncle separates P. patriciae from P. omalonotus.

Pachypanchax arnoulti and P. varatraza both have rounded vertical fins in contrast to P. patriciae whose dorsal and anal fins come to a sharp point. Further diagnostic differences are in that P. patriciae has longer pectoral fins than P. varatraza and a shorter head than P. arnoulti.

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

Loiselle (2006) notes that the percentage of each colour morph varies from population to population. Red males disappear completely from populations as one moves from south to north

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

None known

Ifasy River; Oxbow lake

Mahavavy du Nord River; Tributary of

Antikotazo Creek

Also found in:

P. patriciae currently faces no threats from introduced predators or competitors. Habitat loss in the Mananjeba, Mahavavy du Nord and Ifasy River watersheds currently threatens the survival of the northern-most populations.

Loiselle classifies this species as vulnerable based on WCU criteria (Loiselle, 2006).

Loiselle (2006) states that P. patriciae inhabits two distinct biomes in Northwestern Madagascar: the monsoon (Sambirano) forests of the northwest and the deciduous forests of the extreme north.

Streams of the Sambirano forest region, the Ampandra and Manehoko, limnologically resemble streams from the eastern half of Madagascar in being tannin stained, soft, and lacking in dissolved substances. Substrates of this region typically have a clay/sand mix covered with leaf litter and debris. Typhonodorum lindleyanum (Water Banana) and Nymphaea (Waterlillies) are present in shallow areas but no other aquatic macrophytes were observed.

The Mananjeba, Mahavavy du Nord and Ifasy are more typical of west coast rivers characterized by distinct seasonality in flow, substantial flood plains and numerous shallow lakes (matsabory). Streams are less acidic, harder and carry a greater concentration of dissolved minerals. Substrates consist of clay or sand/clay mixtures covered with organic debris. Marsilea (Water clover) was found in the Mahavavy du Nord along with some clumps of filamentous algae; other rivers from the region did not contain notable populations of aquatic macrophytes.

pH: 5.0 – 7.2

Conductivity: 19 – 74µS

General Hardness: < 18.0 – 71.6ppm

Oreochromis mossambicus

Paratilapia polleni

Ptychochromis oligacanthus

Glossogobius giuris

Tilapia zillii

Anguilla bicolor

No known captive populations currently exist

Unknown but assumed to be typical for other Malagasy Pachypanchax species.

Unknown

In the wild:

In captivity:

Unknown in Captivity

Unknown but assumed to be similar to other Malagasy Pachypanchax species.