History

Described in the genus Austrolebias.

2023, moved to genus Matilebias

Austrolebias paucisquama is known only from the type-locality : a temporary pool in the rio Vacacaí drainage, rio Jacuí tributary, laguna dos Patos drainage, close to an area of extensive use as pasture. This situation places the new species as a critically endangered.

The description refers to Juan Anza, Júlia Giora and Adriana
Saccol Pereira as the persons who collected the species for the first time. However, the Brasilian killibreeder Dalton Nielsen collected this fish in 1989 already and put in the hobby as Cynolebias cyaneus, "Saint Gabriel".
It was reported only once available in the hobby.

Austrolebias cyaneus is distinguished from other species of this group by having fewer scales around caudal peduncle (12) and fewer dorsal-fin rays in males (17-21). The lack of contact organs on the inner surface of the pectoral fin in males and the color pattern of females - ground color light brownish, sides of body with a variable number of relatively large dark black spots distributed mostly on posterior portion of body - distinguish A. paucisquama from all other species of the genus. The name is given after the Latin “pauci” meaning few, and “squama” meaning scales, in reference to the reduced number of scales around caudal peduncle.

Personal additional info from Dalton Nielsen, Brasil, about his early discovery of the species in 1989.

During a collection trip in 1989 to the states of the south of Brazil, I found a species, in the margin of the highway BR- 290 near São Gabriel's city that I identified as Austrolebias aff. cyaneus, from São Gabriel.

The trip began in the city of São Paulo on August 05 1989, winter in southern hemisphere, a good time to find annual fish in the south of Brazil. The objective of the trip was find again Austrolebias carvalhoi, Campellolebias brucei, Austrolebias cyaneus and, maybe, an Austrolebias nigripinnis in Brazilian territory, since a few kilometers of the boundary with Uruguay near Itaqui a population of A.nigripinnis was located.

Uruguaiania was Apistogramma borelli being the most southern registration of this species. Close to São Gabriel's city the climate was already very different, there were several full puddles and in one of them found an Austrolebias now described as A. paucisquama. I continued trip and about 200 more km further on the same highway I found beside "Dom Marcos'" stream A. cyaneus. When comparing the two species I believed to be the same species because of their similarity. No material was preserved for scientific studies; I only distributed the fish among my friend- aquarists as being an A. cyaneus, from "São Gabriel". The other as A. cyaneus, from "Dom Marcos".

As recently the description of A. paucisquama was released I immediately identified it as being the species collected in 1989. The description shows that separating this new species from A. cyaneus is only possible in the laboratory and as in the collection of 1989 we didn't preserve material. Therefore it was not possible to identify it as a new species.

To breed most Austrolebias, you need a tank with about 10 to 25 liter water in it, a small jar or plastic container of about 10 to 15 cm high, a little bit of well-boiled peat moss, or coco-peat, and a water temperature between 18 and 24 C. It is wise to add a small filter to that tank and change the water regularly for 90 %. Bring one male and, if possible, two or more females in the tank and feed the fishes daily with live food like daphnia, red- and black mosquito larvae, and white worms. Austrolebias does not accept dry food quickly, and also, the prepared cow-heart is not preferred if live food is offered. If possible, breed this genus in larger tanks with more than one pair or trio and give some hiding places if you do so. When breeding with more than one male, you should also provide more than one spawning container. Every male must have one, and you will see they show interesting territorial behavior to attract females into their spawning place.

The male "flinders" around the female, displaying his fins high- up with the most intense colors. As the female is willing to spawn, she follows the male, pressing his head towards the layer of peat, and when the female contact the male's belly, both will dive into the peat layer. This layer should have a thickness of at least the length of the largest animal or, better, some deeper so they can dive entirely into it.

The spawning occurs during the whole fertile life of the fishes, starting at 5 to 6 weeks of age, till they become old and weak or die from the lack of water in their natural environment. This "end-of-life" will be within 8 to 11 months, depending on the temperature. Higher temperatures will trigger more rapid aging.

In the wild, Austrolebias live in colder environments during the wintertime. Temperatures in Uruguay, Paraguay, and Argentina can get very low. Incubation time usually is six weeks if stored at high temperatures ( 25 C.) and more extended if kept at lower temperatures. The development can last five to six months also. So it is wise to check the eggs regularly to see if the eyes inside the eggs are fully developed and the iris is well visible. When "eyed-up," put a part of the peat with the eggs in water at cool (ca. 18 C) temperature. If the fry usually hatches- and swims within a few hours, wet the rest of the peat. After hatching, feed the fry immediately with freshly born Artemia nauplii. A day or so later, I pour the water together with the fry off and place them in a well-filtered tank without any peat moss to grow up. Austrolebias are not used to strong currents, and juveniles can die if turbulence is too strong. The remaining peat will still have eggs inside that are not ready to hatch yet. Re-pack the peat and store it for some extra time. This hatching delay is nature's answer to short rain showers that fill pools only temporarily, followed by another dry period. Such an event would kill the entire population of the species in that area if all eggs were hatched with first rains. These (late) eggs will hatch later, sometimes very much later, and the fishes that were born earlier will eat these youngs.

As stated before, young's are growing fast and will produce their first eggs after 5 to 6 weeks already, if not even sooner. This breeding information applies to most Austrolebias. However, if the above Austrolebias- species have different behavior or extreme adult size, find these adaptions below in this chapter under <remarks>.

Remarks;

Ferrer dos Santos, J., Malabarba, L.R. & Costa, W.J.E.M., 2008. Austrolebias paucisquama (Cyprinodontiformes: Rivulidae), a new species of annual killifish from southern Brazil. Neotropical Ichthyology, 6(2):175-180. (PDF) Right click to open in new window.

Alonso F., G.E. Terán, W.S. Serra Alanís, P. Calviño, M.M. Montes, I.D. Carcía, J.A. Barneche, A. Almirón, L. Ciotek, P. Giorgis, J. Casciotta, 2023. From the mud to the tree: phylogeny of Austrolebias killifishes, new generic structure and description of a new species (Cyprinodontiformes: Rivulidae) Zool. Journ. of the Linnean Society, XX, 1-30, Fig. 15, Tab. 2.