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.
In the late 80's 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 four trips were made to Nicaragua. He visited most of the crater lakes in this 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 and giving presentations around the globe. 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 informally known as "heroine cichlids".
- Belize, searching for cichlids: This presentation 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.
- Heroine cichlids: an addiction?: An introduction to a fascinating (addictive?) group of Neotropical cichlids. The presentation addresses three questions: 1. What are heroine cichlids? (classification and phylogeny); 2. Where can heroine cichlids be found? (current and past distribution in a changing landscape); 3. How can heroine cichlids be recognized? (morphological characters and an overview of the genera/species). The presentation may be challenging at times, but every effort has been made to avoid technical terms and reach out to the hobbyist. To that purpose the presentation is also richly illustrated with fish pictures as well as video.
- 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 presentation covers the way to build such a fish house (stands, tanks, water supply, lighting, etc) and closes with a report on some dramatic events that can happen to you on the way.
- Nicaragua, cichlids from the crater: During four trips to Nicaragua I visited eight 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 presentation. Special attention is given to the cichlids belonging to the Amphilophus citrinellus complex that has undergone interesting evolutionary processes in the craterlakes. The videoclips of this presentation have been edited into a one hour film and released on DVD (copies available at the event).
- Nicaragua, searching for cichlids: Besides visiting the craterlakes I have also travelled other parts of Nicaragua extensively. This presentation 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 presentation 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 discussed. 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 presentation the places to visit are marked on a map of México. A river drainage will be selected of which pictures and (in most cases) a video will be shown. Together with the (sometimes amusing) stories this makes an excellent way of getting to know this beautiful country and its cichlids. The videoclips have also been released on DVD (copies available at the event).