Willem has been a member of the Dutch cichlid association (NVC) for over 35 years and has served as their President for well over 12 years.
About 15 years ago he started collecting cichlids in México and other countries in Central America. Most of these trips he made together with Ad Konings and some with Juan Miguel Artigas and Don Danko. On the first trips he focussed on collecting cichlids but on later ones Willem tried his hand at shooting video both above and below water. This has resulted in bringing (new) cichlids into the Dutch hobby and a number of films, a compilation of which is available on the DVD "México, a journey into the world of cichlids".
His last three trips were made to Nicaragua. He visited most of the crater lakes in that beautiful country searching for cichlids, concentrating on Laguna Xiloá where he put his diver’s license to good use being able to get video footage from depths of 20 meters or more. This footage was edited to produce the DVD "Nicaragua, cichlids from the crater" which is also available to the public.
No longer keeping cichlids, Willem is now concentrating on writing. He has published a number of articles about cichlids in magazines worldwide and has also co-authored a book on these wonderful fishes. His main area of interest is the evolution and systematics of Neotropical cichlids belonging to the tribes Cichlasomatini and Heroini.
- Belize, searching for cichlids: This talk comprises a travel report to the beautiful country of Belize (just east of México). Visits were made to the rivers and lagoons trying to find cichlids both for filming and collecting. There’s footage of cichlids in many rivers as well as an exciting boatride with a local fisherman on Freshwater Creek.
- Central America, breeding cichlids in the home aquarium: Here’s an overview of my experience with breeding Central American cichlids. It contains some surprising information on their husbandry and many species reports, including the (best?) way of selecting between the many fry some species can produce.
- Central America, history of the area and origin of its cichlids: A challenging talk about when and how the landbridge we now call Central America was formed and how the cichlids came to occupy this new land. Information on the phylogenetic relationships of the many cichlid taxa are given, as well as an overview of their great diversity. Many species are presented in beautiful pictures and the talk closes with footage of one of the most interesting species for the larger home aquarium.
- My Cichlidarium, a personal history: Keeping cichlids on a larger scale requires adequate facilities. Therefore I have created a fish house (the Cichlidarium) that suits my needs, especially for keeping big cichlids. This talk covers the way to build such a fish house (stands, tanks, water supply, lighting, etc) and closes with some dramatic events that can happen to you on the way.
- Nicaragua, cichlids from the crater: During three trips to Nicaragua I visited 8 of this beautiful country’s craterlakes. I managed to get footage in the majority of these lakes, showing the behaviour of cichlids in their natural habitat. An exciting example of altruism (still heavily debated among scientists) completes this talk. Special attention is given to the cichlids belonging to the Amphilophus citrinellus complex that has undergone interesting evolutionary processes in the craterlakes.
- Nicaragua, searching for cichlids: Besides visiting the craterlakes I have also travelled other parts of Nicaragua extensively. This talk is a travelogue of these trips. It contains footage of the cichlids occurring in the rivers in the northern and eastern parts of Nicaragua.
- Cichlasoma, rise and fall of a cichlid genus: This talk is more or less scientifically orientated and gives an overview of the reasons and backgrounds of the (many) name changes some of our cichlids have undergone. Using Cichlasoma as an example, the taxonomic history of the many species that once belonged to this genus is presented. The main conclusion is that every name change is really adding to our knowledge of the species concerned. And we are still learning....
- México, a journey into the world of cichlids: In this interactive presentation the audience decide which places to visit. On a map of México all places that I visited are marked. The audience picks a river drainage and then pictures and (in most cases) a video is shown of that drainage. Together with the (sometimes funny) stories this makes an excellent way of getting to know this beautiful country and its cichlids.