Akula (Shark), Homyak (Hamster), and Volchonok (Wolfie): all the river giants have their names
Two kaluga sturgeon, the largest freshwater fish in Russia, are really the gems of the Rivers and Lakes exhibit. There are six more of these giant fish in the Science and Acclimation Building, kept together with their relatives, sturgeon and carp. Special fish need special attention: the kaluga and their neighbors have personal diets and are hand-fed.
“Our divers feed them by hand to ensure that every fish gets what it needs, and the larger individuals don’t take the smaller ones’ portions,” tells Denis Perov, diver. “First, we feed the carp, the little ones. We call them ‘piranha’, because, if they are not fed, they’re always importuning and taking food from the sturgeon: they attack one fish and start biting, pinching and pecking, thus forcing it to lose hold of a snapped morsel. They are far from being modest with us, too. You hold a piece of food, they stay waiting for some time, as if asking: “May we?...” and then just grab it and flee.”
The sturgeon are the next to have meal after the carp. They have the same diet, mostly consisting of salmon: chum and humpback salmon, char, - though the carp don’t like the latter and sometimes spit it out. The fish filet is cut into long strips, fit for the sturgeon and the carp.
“They usually swallow two morsels in one bite or sometimes cram their mouths with food like hamsters and then chew and chew it for 5–10 minutes,” explains Denis Perov. “The carp and the sturgeon rarely want to interact with us, only some carp are willing to play, letting us to scratch them, to put them upright on their nose or to turn them over. Our kaluga are different: every fish is a personality, with specific hunting or food preferences and individual behavior towards humans. That is why every fish has a name, given mainly for some external traits. The fattest male is called Homyak (Hamster); he weighs 240 kilos and has cheeks—you can touch and feel them. Kurnosyi (Snub-Nosed) has a peculiar nose. Koza (Horns) got her name due to a rock-and-roll sign of horns pattern on her head. The longest kaluga, almost two meter in length, and also the fiercest, is Akula (Shark). She often fights and provokes others. Malyshka (Babe) is a very independent girl. You have to persuade her to eat, and first she becomes indignant at being suggested a whole fish, but finally takes it. The kaluga having the longest snout is called Volchonok (Wolfie). He is my favorite, most affectionate of all. He likes to play and even allows pulling his tail while others are too dangerous to be approached from behind. These fish have very strong tails, the blow of which feels like a professional boxing punch, Akula’s one being the most perilous.” The diet of the kaluga mainly consists of mackerel, which is very nutritious. Each kaluga eats three to four whole mackerel at one feeding.
“The kaluga’s feeding behavior is peculiar: the fish opens its mouth wide and sucks food up like a vacuum cleaner,” points out Denis Perov. “You have to be very cautious: if you don’t let go a piece of food in time, the mouth may suck up your arm. It won’t be bit off, but the situation is still very unpleasant!”
All the kaluga in the Primorsky Aquarium are of the same age, they were born in 2008. Though they are 150 to 210 cm long, they are still teenagers. The kaluga sturgeon grows without haste and becomes mature generally by 18 years of age.
General information:
- The kaluga, Huso dauricus, is a freshwater fish inhabiting only the Amur River basin from the estuary to the upper reaches. It can be found in the Argun, Shilka, and Sungari (Songhua) rivers.
- The kaluga can reach a length of 3.7–5.6 m and a weight of 800–1000 kilos.
- Its life span is 48–55 years.
20.10.2021