One of the most numerous and beautiful fish in Lembeh is the Banggai cardinalfish. Just a few years ago, this small black and white fish with delicate patterns was quite rare in the strait, but now it can be seen almost all through Lembeh. Yesterday I saw quite a number of them at Aw shucks, which is about as far northeast as you get in Lembeh. Also they can be found in very high densities at some places. For example, they are by far the most common fish in the police pier area and are increasing in numbers even elsewhere.
Banggai cardinalfish originate from the islands of Banggai in Indonesia. Their habit of mouthbrooding their eggs till the young are quite big limits their dispersion Thus, they are endemic to Banggai, which means that this is the only place they are found.. Well, at least till marine aquarists entered the scene. Banggai cardinalfish are pretty hardy, beautiful and they were comparatively cheap, none of which is common for marine fish for aquaria. Furthermore and maybe most interesting, the Banggai cardinals can be held in groups as they are much less aggressive towards conspecifics than most other marine fish.
So Banggai cardinals entered the hobbyist fish market in vast numbers. They were caught in Banggai to the extent that several of the populations there are very rare, and were shipped to major ports in Indonesia, such as Bitung here in Lembeh, from which the were exported to oversea locations. They were held in seine nets until export, and, of course, someone screwed up and a bunch of Banggais escaped into the strait. Contrary to common belief, introduction of foreign species is not easy, but the Banggais thrived in the strait and are now very common, to the extent that it would be hard to do a dive here without seeing one of them.
So, is this a joyous story where a species hunted to the verge of extinction in its home place finds a sanctuary and is saved? And wouldn´t the gentle and beautiful Banggai cardinals, with their interesting habits of having the males brooding the offspring in their mouths be a perfect introduction to almost any marine environment? Well, you do not hear a lot of cheers and hand clapping for the Banggais in Lembeh. The next blog entry will explore why that is so. What a cliffhanger! But in less than 24 hours, you will have the answer!