 Introduction to It Rains Fishes |
To all visitors of this site
Frans Vermeulen, initiator of this <It Rains Fishes> site welcomes you and wishes that you will get just the information out of it that you look for.
This site is meant for hobbyists and scientists that like to know more about the Killifishes of South- and Middle America. Content however is not to be seen as pure scientific. I follow in here the most recent view in nomenclature as presented in Killi-Data Online by Dr. Jean Huber. Additional information is generated from literature as <A World of Killies> by R.H. Wildekamp and <New World Killies by Dr. L. Seegers. Also historic- and new manuscripts from scientists all over the world are consulted as a source of information.
At the left column in the main page most genera of the Rivulidae are listed and additional genera will be added as time will go by. By hovering the genus names with your mouse pointer the species names and a short introduction of that genus will appear. If clicking a species name info appears and you can click the images to have a closer look. The links at the top of the species page give access to different parts of information as short history, how to reproduce the species, maps and if available images of the species habitat. If literature is available online you can download it also by choosing the linked text given in <Literature> and open it in a new window if you choose to do so.
At the top of the mainpage some links give access to all other sections of this site. You may have interest in the expeditions I made to discover scientificly known, but also never discovered species, in their habitat myself. For that there is a link called: < Expeditions>. You may have a question or like to help me with PDF files, species-info or images getting this site more complete. If so.... please mail me by using the form.
Introduction
There are many biogeographic areas that do not have sufficient rainfall through- out the year. As a result of that some fish habitats evaporate on a seasonal cycle . Some of the Rivuline lineages did adapt to this cycle and developed an annual lifestyle that meets their environment.
Imagen, these genera became able to survive dry periods by producing eggs that can survive in the soft bottom layer. So, if the water disappears the eggs remain and the population can continue to inhabit these temporary waters through there offspring.
“It Rains Fishes” therefore is the Amerindian explanation to this natural wonder because, after the first rains fall, whitin hours juvinile fishes appear where no water was left during a long period of time. These species must grow very fast to become adults within several weeks or months and start reproducing early to survive as species the next dry season which can last also several months to, in some cases, occasionally more than a year.
This adaptation is also seen in African genera like Nothobranchius and scientist do not agree what type of behaviour was first. DNA analyses indicate evidence that annualism developed out of non- annual behaviour. Annualism however is very common in the South- American Rivulid world and the number of annual genera is much larger than the number of non-annual genera like Rivulus, Prorivulus an Kryptolebias.
In the past decade, a lot of species belonging to one single genus were split into several genera by scientist as a result of the need to get a more clear view of the different lineages in the evolution of these fishes.
A great number of the new genera were lately erected by the Brazilian scientist Dr. Wilson Costa.
The genera:
The oldest known are Austrofundulus, Cynolebias, Cynopoecilus, Leptolebias, Pterolebias, Rachovia, Simpsonichthys and Trigonectes. Many of them are now divided into several other genera.
More recent erected genera are Aphyolebias Costa 1998, Austrolebias Costa 1998, Campellolebias Costa et al. 1989, Gnatholebias Costa 1998, Maratecoara Costa 1995, Megalebias Costa 1998, Micromoema Costa 1998, Millerichthys Costa 1995, Neofundulus Costa 1998, Papiliolebias Costa 1998, Pituna Costa 1989, Plesolebias Costa 1989, Renova Thomerson & Taphorn 1995, Simpsonichthys Costa 1996, Spectrolebias Costa & Nielson 1997 and Stenolebias Costa 1995.