While photographing a pair of kissing gourami (Helostoma temmincki) at the DesMoines Public Aquarium in Iowa, an inquisitive thought teased my mind as to the reasons for this strange little ritual that I was observing. A lady nearby was overheard to say, "My how cute, they're kissing each other." Her statement was a reasonable and accurate one regarding the strange phenomena she had seen but I was led to search for a more concrete answer to this "fish-kissing' business.
I sought out Billy Arnold, aquarist of tropical fish at the aquarium. Billy has been with the aquarium for nine years and maintains about sixty tanks varying from ten to 700 gallons. The descriptive sign on the tank had provided an explanation as follows: "The kissing gourami is so-called because of the kissing-like, aggressive encounters in which the lips come in contact. This species lives in S.E. Asia and attains a length of 12 inches." I asked Billy about this interesting piscatorial behavior, to which he replied, "I believe it is an act of mating and courtship. From numerous observations made I have never known males to 'kiss' one another. The young do not 'kiss' either, until about 6 to 8 months old." I asked him how he could tell the difference between the male and female visually, since they had both appeared identical to me. His answer was, "The top dorsal fin in the male is noticeably longer." Further questioning disclosed some valuable information that would be of worth to those aquarists contemplating the addition of Helostoma temmincki to their aquariums.
There seems to be a great diversity of opinion as to the distinction of the word gourami, goramy, or gurami, both in the correctness of spelling and in its application to certain fishes. The kissing gourami belongs to the family Anabantidae (some, for example Liem, place it in the family Helostomatidae) and the species name is Helostoma temmincki. The first known description of this species is attributed to M. le B. Cuvier and his aid M. Valenciennes in their book Histoire Naturelle Des Poissons, 1831. The several authoritative sources were generally in agreement that Helostoma temmincki' s natural habitat was in the rivers of Java, Borneo, and Sumatra. It was stated that they had been introduced into the fresh water rivers of Sri Lanka in the sixtys.
Courtship of these naturally likeable little fish involves such various actions as following each other, chasing, swimming to the nesting site, backward swimming, mouthing, nipping, erection of fins, and other unusual behavior. In their breeding habits they are known to be bubblenest builders and perform an embracing ritual wherein the eggs are deposited in the nest. They are herbivorous fish with moveable teeth, but have been described as being omnivorous" (the indiscriminate, greedy, habit of eating food of all kinds) by Dr. Gunther Sterba in his book Freshwater Fishes of the World.
There are several theories as to why Helostoma temmincki kisses, but actual scientific proof seems to be lacking. As L. P. Aronson states that assumptions are often made about the nature of aggressive and reproductive behavior without adequate evidence about what is actually taking place. Three main theories seem to be: 1) That kissing is an aggressive action derived from the formation of territories and social organizations. 2) That it is an act of courtship and/or presexual behavior. 3) That it is merely a habitual play trait, characteristic of other fishes also. A more recent suggestion claims that may possibly be a method by which the fish remove tiny parasites from each others mouths. An extensive research in the future may finally solve this mystery; until that time, however, this strange little ritual remains the secret of Helostoma temmincki.
Well at least I can finally say that my inquisitiveness
has now been satisfied or has it? I still don't know why kissing gourami
"kiss" each other.