Study describes Leptobotia loach spawning behaviour


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Scientists have published a study describing the spawning behaviour of an endangered species of loach from the genus Leptobotia.

The Kissing loach, Leptobotia curta, a member of the botiid loach subfamily Botiinae, is found in Lake Biwa in Japan and is considered to be an endangered species.

Scientists from Japan spent two years observing the species in the wild and found that the loach spawned in temporary waters following a rise in the water level due to prolonged rain.

More than 160 separate spawnings were observed and all lasted three to five and a half hours and took place from late afternoon to night following the rise in water level.

In 71% of spawnings a single male and female spawned in densely vegetated moving water, however, in 29% of spawnings two males were present.

The female Leptobotia curta followed the male into mats of dense aquatic grasses and vibrated resulting in intermittent spawnings.

The authors said: After the vibration continuing for 3-20 seconds, they moved to other parts of the dense grassy area and began vibration again.

This sequence of spawning behavior was usually repeated several times, and the eggs were thus scattered widely.

The spawning behavior and the rapid larval development of this species appear to be adaptations for the use of temporary waters as a spawning ground.

The rise in water level and the consequent formation of temporary waters appear to be crucial triggers for reproduction of the Kissing loach.

The paper represents one of the few documented examples of the natural reproductive behaviour of botiine loaches.

Leptobotia curta has been recorded mainly from Japan's Okayama Prefecture, but museum records also show that the species has been collected from Fokien Province in China.

The species reaches a size of around 15cm/6 in standard length.

For more information see the paper: Abe T, Kobayashi I, Kon M and T Sakamoto (2007) - Spawning behaviour of the kissing loach (Leptobotia curta) in temporary waters. Zoological Science, 2007 Aug (24) 8: 250-3.