Define Killifish

In My Humble Opinion
1

“Some of the egg-laying tooth carps”; so why are some ELTC’s killis and some not?
Why are Gambasia which do not lay eggs considered by some books to be killis?

2

I work with the mummichog (Fundulus heteroclitus), the least pretty of all the killis.

I’m looking in my handy Biology of Fishes and it says here that Gambusia belong to the family Poeciliidae (livebearing toothed carps). Killifish fall under Cyprinodontidae (egglaying toothed carps). So as far as I can tell, there isn’t a problem.

3

Schrenkeisen, Ray Field Book Of Fresh-water Fishes of North America, North of Mexico (whew!) G.P. Putnam’s Sons, NY 1938 says Gambasia patruelis (Has been called Gambasia affinis)…“A small viviparous killifish…”

I’ll concede that things have changed in almost 70 years, but how do Killies differ from other Cyprinodontidae?

4

Killifish can be either oviparous Cypriniodontidae OR ovoviviparous Peociliidae. These are closely related families and I believe the confusion arises because the term ‘killifish’ predates the separation of the “Cyprinidontiform” fishes into different families. At any rate this is not an uncommon problem with animals, fish in particular. There are a multiplicity of fish with the common name ‘Sheepshead’ for example, or ‘Bass’. This just goes to show why unique Linnean binomials are used in scientific literature, rather than just common names :).

  • Tamerlane
5

Urk. Poeciliidae.

  • Tamerlane
6

Oh and just in case there is confusion, viviparity has two definitions in regards to fish. The less precise ( but more common
laymen ) definition is any seemingly “live-bearing” fish. But the more precise definition is a fish that nourished internally by the mother. Ovoviviparous fishes develop internally, but from there own egg resources - There is no parental nourishment. Poeciliidis are therefore not viviparous by the stricter, more correct definition.

  • Tamerlane
7

Here’s the classification of Cyprinidontiforms as written up by my former Ichthyology professor Lynn Parenti ( now Director of Vertebrate Zoology at the Smithsonian - I’m so proud :smiley: ):

http://www.killi.net/cyprinod.html

  • Tamerlane
8

I am, I suppose, relieved to find Mr. Schrenkeisen vindicated; let me take this opportunity to rephrase the OP:

Are all Cyprinodontidae killifish?

9

carnivorousplant: Here you go:

http://www.killi.net/nwslarts/nlar381.html
So to be thoroughly confusing after that article…

…Cyprinodontids are Killifish, except when they’re Pupfish :wink: :

http://artedi.fish.washington.edu/FishKey/killi.html

http://www.fishbase.org/Summary/FamilySummary.cfm?ID=212

…except this guy that says they are all Pupfishes and it’s the family Fundulidae that are Killifishes:

http://people.clemson.edu/~jwfoltz/WFB418/subjects/pupfish/pupfish.htm

…but are the Fundulids Killifishes or Topminnows :smiley: ?:

http://www.biology.ualberta.ca/jackson.hp/IWR/Taxa/Cyprinodontiformes/Fundulidae/index.php

…while the Goodeidae, which according to Lynn are a little more closely related to Cyprinodontids than Poeciilids, are “splitfins” or “springfishes”. Or Killifishes :smiley: :

http://nas.er.usgs.gov/fishes/accounts/goodeida/goodeida.html

Basically the name has no real scientific correspondance. It is used for a variety of fish in a large, related group of minnow families, with no real consistency. So a Killifish is whatever you want to call a Killifish ( or is accepted as a Killifish by whatever group of people you’re talking to ).

Not very satisfying, is it? :slight_smile:

  • Tamerlane
10

Thanks.
And thank goodness for Linneus. (sp)
:slight_smile:

11

…and here i thought that it meant “a thousand fish.”