Live -bearing Killie?

[timebomb]

Gustavo mentioned in his post in the "Planted Tank" forum that he has a trio of Cnesterodon decemmaculatus which he says is a local live-bearing Killie. Local in Gustavo's case would be Buenos Aires, Argentina.

I'm surprised. Aren't all Killies egg-layers? The very name, Killifish is supposed to mean "Egg-laying toothcarps", right? So how can a live-bearer possibly be classified as a Killie?

Please enlighten me. Thanks.

Loh K L

[gacp]

Killifish, the common name for oviparous cyprinodontiformes fishes, are currently classified into 10 families (Huber, 2005):

- Aplocheilidae, only from India and Madagascar;
- Nothobranchiidae from Africa but Madagascar with 2 subfamilies: Nothobranchiinae and Epiplateinae;
- Rivulidae from Central and South America with 3 subfamilies: Rivulinae, Cynolebiinae and Kryptolebiinae;
- Fundulidae;
- Profundulidae, monotypic (which may be included also in Fundulidae as a subfamily or in Goodeidae as a subfamily, depending on authors);
- Goodeidae, with 2 subfamilies: Empetrichthyinae, oviparous and Goodeinae, viviparous;
- Valenciidae, also monotypic (which may be included also in Fundulidae as a subfamily, depending on authors);
- Cyprinodontidae, with 2 subfamilies: Cubanichthyinae and Cyprinodontinae (with the latter in 3 tribes, Aphaniini, Cyprinodontini and Orestiadini);
- Anablepsidae, with 3 subfamilies: Anablepsinae, viviparous, the monotypic Oxyzygonectinae, oviparous, and Jenynsiinae, viviparous;
- Poeciliidae, with 2 subfamilies: Poeciliinae viviparous (except the monotypic subtribe Tomeurina -or tribe as Tomeurini, depending on authors-, oviparous) and Aplocheilichthyinae oviparous (in 3 tribes, Aplocheilichthyini and Procatopodini in the Old World and the monotypic Fluviphylacini in the New World).

http://www.killi-data.org/zz-discoverPyramidal.htm

This is based in Parenti's work, which, of course, is not available (truly published)

Parenti, Lynne R. 1981. A phylogenetic and biogeographic analysis of cyprinodontiform fishes (Teleostei, Atherinomorpha). Bulletin of the American Museum of Natural History, vol. 168, pt. 4, pp. 335-557.

Done with public funding, but locking people out, so you cannot read it, as I did (more like skimmed, actually). See why I left science?


Anyway, poeciliins---which are not all livebearing, BTW---are just killies. Makes perfect sense... and also make killies the most popular aquarium fishes


Now, if I just could come out with an excuse to banish haplochromines (sensu lato) out of Cichlidae, har har har

[fish newb]

i believe the ones he was refering to was a common name "least killiefish." they arent a actually killiefish. they where in swap and shop section. i almost got some. very interesting fish. they are native to Sout Eastern USA.

- andrew

here is the link to what i think you where talking about

http://www.plantedtank.net/forums/sw...andria+Formosa

[gacp]

i believe the ones he was refering to was a common name "least killiefish." they arent a actually killiefish. they where in swap and shop section. i almost got some. very interesting fish. they are native to Sout Eastern USA.

No, what I meant is that all poeciliids are actually killies (including of course Heterandria formosa), livebearing killies, and that I think it makes far more sense not to exclude poeciliids, anablepids, and goodeids arbitrarily---they are true killies in all respects notwhithstanding their livebearing reproduction. And in fact, at least one 'livebearer' (Tomeurus gracilis) is an egglayer just like any plesiomorphic (primitive) killie.

[fish newb]

so if i understand correctly this is actually a true killiefish? it is a amazing fish.

im new to the whole killie thing....

- andrew

[whuntley]

The name "killifish" was chosen by hobbyists, mostly the US group, about 50 years ago. The prime contender, at that time, was "panchax."

It was done with minimal taxonomic concern, but was clearly exclusive to the egg-laying species of the Cyprinodonts. Many livebearers are very close relatives, but they are not killies, simply because they do not lay eggs.

Labelling the Het. formosa as the "Least Killy" was without either scientific or hobby approval. Nevertheless, it is a cute fish, and was thought to be the smallest vertibrate at one time (some gobies are quite a bit smaller).

The closest line-blurring between livebearers and killifish are those SAAs that are internally fertilized, but still lay their eggs for hatching, like Cynopoecilus melanotaenia. Livebearing species cannot live through drying up in droughts, so egg-laying provides a way around that. Internal fertilization may give the female more chance to hide the eggs, since the male isn't there to see them deposited.

Nature is wonderfully diverse, but killifish are egg-laying toothed carps, by definition.

Wright

[gacp]

Nature is wonderfully diverse, but killifish are egg-laying toothed carps, by definition.
Wright

That would include Tomerus gracilis, and only Tomerus gracilis, as a killie, since this poeciliin species lays eggs.

Knowledge accrues and improves, and words change accordingly. Killies, to me at least, is the common name for Cyprinodontiformes.