Posted by rocksea on 24 Feb 2011
The stone suckers (sp. garra mullya ,malayalam: kalle-mutti) are one of our favorite fish species. They get their name from their habit of sticking to the rocky substratum in the streams. If you dip your legs into some of the streams or rivers in the western ghats/kerala with rocky substrates, chances are that you get tickled by these fishes lapping up your feet. They will give you a wonderful pedicure!
The ahesive apparatus consists of a sucking disc as part of its mentum (the protruding part of the lower jaw) along with modified lips and paired fins (see the blown-up image below), which enable the fish to adhere to rocky substrates in torrential streams. Adhesion is performed suctorially by the callous (thick) portion of the disc. The lips and the fins act as frictional devices to prevent skidding and assists the mentum. It is usually the adults which stick to the rocky substrates and feed the algae while the juveniles are found throughout the water column, generally free swimming in search of food. They are also found to ascend small, rocky streams to breed.
Garra mullya is also a macrosmatic fish with a predominantly developed olfactory faculty. Macrosmatic (macro+osmatic) means they are having a highly developed organs of sense/smell (like sharks, dogs). For terrestrial air-breathers, olfaction is defined as the detection of stimulant molecules in the air, by its nose. For fishes, the process is called gustation – as they are in the aquatic environment – the carrier of stimulant molecules is not air but water.
The sample fish here is from the collection in our fish pond, originally from the Meenachil River, Western Ghats.
Hara TJ, 1975. Olfaction in fish. Progress in Neurobiology. 5:271-335 [source]
Saxena SC, 1959. Adhesive apparatus of a hill-stream cyprinid fish garra mullya (Sykes). Proceedings of the National Institute of Sciences of India, B, 25(4): 176-188 [pdf source].
Saxena SC, 1960. The cranial musculature of a hill-stream cyprinid fish Garra mullya (Sykes). Proceedings of the National Institute of Sciences of India, B, 26(4): 176-188 [pdf source].
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