Pterapogon Kauderni – The Banggai Cardinalfish


The Banggai Cardinalfish (or of the Moluccas), Pterapogon Kauderni, comes from the territory between Sulawesi and Moluccas. Its diffusion is localized near the island of Banggai, therefore within the English language it is associated with the popular name “Banggai Cardinal”. Back in 1920, the fish was captured by Dr. Kaudern in Indonesia, and 13 years later it was scientifically described by Koumans, but from that time on it had been almost forgot. Only in 1992 an underwater touristic entrepreneur, Kal Muller, saw this unknown fish at the island of Banggai. He sent some photos to Allen, in Perth, who after a long research stated that a sample individual was conserved at the Museum of natural history in Leiden, so that the species was rediscovered 60 years later.


P. Kauderni does not live in the coral reef. Its typical habitat is provided by the algae beds, in which it stays in small groups of 2 to 60 individuals, often among the long spines of urchins belonging to the Diadema kind.


The body is silvery and crossed by black vertical stripes, which is probably an adaptation to the environment of the algal beds. Among the black spines of the Diadema urchin, the vertical body bands help the fish to dissolve its own contours just like among the algae. The big eyes, as typical of this family, indicate a crepuscular and nocturnal lifestyle.


P. Kauderni reaches 6 centimeters in length.

Pterapogon Kauderni – The Cardinal fish of the Moluccas

Pterapogon Kauderni – The Cardinal fish of the Moluccas


In aquarium, the cardinal fish of the Moluccas in the daytime mainly stays near the decoration and gladly stops under a rocky jump too. The fish concentrates on the careful observation of the surrounding environment, but as food is administered it can also approach very quickly. Despite the mainly nocturnal activity, normally during the day it does not hide. These animals feel comfortable in groups, but after the formation of the couple they become territorial and may result as very aggressive towards their own conspecifics. It is important to maintain a temperature between 24 and 28°C, and a moderate circulation of the water.


The reproduction of P. Kauderni is much easier than that of many others marine fish. For this purpose it is very suitable to use a little thematic tank (around 100 liters), in which only one couple is maintained. The male not only brings the eggs until the hatching, but it also does the same for several days with the newborns, whose number normally varies between 20 and 30. In the father’s mouth the young fish feed on their sac-fry. These, which then tend to form a dense school, should be fed at least three times a day. For this purpose the just hatched artemias, which before the administration can be enriched with a nutritious solution, are suitable. Many aquarists report better successes when the young fish are maintained in small groups of few (and equally big) individuals, because in this way the weakest ones have a better chance of survival. As early as after a few weeks the male will be able again to bring eggs in its mouth. If you breed at the same time several groups of young fish with a different age, the presence of the Diadema urchins is particularly important. The youngest fish among the spines find a refuge from their older (and cannibal) brothers.


In nature the cardinal fish of the Moluccas mainly feeds on small crustaceans. In aquarium the living or frozen Mysis, the frozen adult artemias, shredded fish and lobster eggs are more suitable than others. The species (at least initially) does not accept any type of dried food, and even various types of frozen foods are spat back, especially when they are of bad quality.


Given that these fish let themselves be reproduced quite easily, they have quickly found many aficionados among the aquarists. Considering the very limited diffusion of this species, it is really important that as many individuals as possible come from the reproductions. Only those aquarists who also want to attempt their reproduction should buy them. Already today, after such a short time, the natural population is excessively exploited and therefore menaced. Should the import of so many capture individuals continue, the cardinal fish of the Moluccas could actually become a victim of the marine aquarists.