he common name of the Asian Fighting Catfish may just
tell you a little bit about the nature of this months
subject on our Factsheet of the month series for May
2024.
Olyra
longicaudata - with
extended upper lobes of the caudal fin
In a few publications the genus Olyra has
been placed in its own family Olyridae: sub family
Olyrinae. The family was erected by Hora in 1936.
Mo (1991) revised the Bagridae family and proposed
a new classification for Olyra. He classed
on a cladistic pattern focusing on osteological characters.
On the basis of his cladogram of the Bagridae family
it was found the Olyra is deeply nested within
other bagrid genera and as such cannot be retained
as a separate family.
Olyra
longicaudata - dorsal
view
The background
on McClelland who discovered this species tells us
that Sir John McClelland (1805–1883) was a British
medical doctor with interests in geology and biology,
who worked for the East India Company. McClelland
was appointed in 1836 as the secretary of the "Coal
Committee", the forerunner of the Geological
Survey of India (GSI), formed to explore possibilities
to exploit Indian coal. He was the first to propose
hiring professional geologists for the task. He was
also involved in surveys of forests and his reports
led to the establishment of the Forest Department
in India.
He also served
as an interim superintendent of the Calcutta Botanical
Garden from 1846 to 1847 and was editor of the Calcutta
Journal of Natural History from 1841 to 1847. He also
communicated with Charles Darwin with his many letters
of correspondence.
Distrbution:
Asia:
India and Bangladesh. Base of Darjelling Himalaya,
Assam, India; Tenassarim, Myanmar. Type
locality: Kaysah Mountains.
Olyra
longicaudata
was described from the Khasi Hills in Meghalaya,
India (McClelland 1842). This species is known
from the Brahmaputra River drainage in India,
river drainages in Myanmar and the Mae Khlong
River drainage in western Thailand. Their
distribution was extended southwards in India
with the discovery of Olyra astrifera
from Kerala (Mishra,
A. 2024).
The
species is found in swift streams, generally
with a substrate of rocks and sand (H.H. Ng).
In Bangladesh it used
to be seen in high numbers during the 1970s
underneath the rocks and boulders along the
Sylhet-Shilong highway. Because of the large
scale extraction of rocks and boulders from
these habitats, the species is rarely seen
these days.
Remarks:
Olyra kempi Chaudhuri, 1912 is now
a synonym of O. longicaudata.
Common
Name
Asian
Fighting Catfish, Bannertail Catfish
Synonyms
Olyra
longicaudatus, Olyra kempi
Family
Bagridae
Subfamily
-
Distribution
Asia:
India and Bangladesh. Base of Darjelling Himalaya,
Assam, India; Tenassarim, Myanmar. Type locality:
Kaysah Mountains.
Size
11.0cm (4½ins)
Temp.
16-22°C (63-71°F)
p.H.
6.0-7.0.
Characteristics
Rayed dorsal fin inserted
nearer to adipose dorsal fin origin than to tip of
snout and without any spine. Adipose fin extending
up to about an eye diameter behind last anal fin ray.
Pectoral fin not reaching pelvics, spine strong, serrated
on both edges. Pelvic fin not reaching anal fin. Anal
fin rays increasing in length posteriorly but not
reaching caudal fin base. Least height of caudal peduncle
2.2 in its length. Caudal fin lanceolate with central
rays elongated.
Colouration
Redish-brown body colouration.
A narrow and faint dark band along the lateral line.
Two pale brown bands, one above and the other below
the band along the lateral line. Barbels blackish.
Aquarium
Care & Compatibility
Olyra are generally known for their unbearable
nature towards their conspecifics and fatally injuring
each other in the home aquaria. Which is why they
are called fighting catfishes. If multiple specimens
are to be housed in a single tank they must be provided
with ample amount of hiding places and the tank size
must be large enough so that separate territories
can be established (Mishra, A. 2024). Will fit into
a community tank alongside other Asian fish such as
the larger species of Danios and Barbs.
Reproduction
Not recorded.
Breeding Olyra longicaudata in captivity
can be challenging due to the lack of available information.
Sexual
differences
Not recorded
Diet
They
are easy to feed as they accept dried pellets easily.
But some species or specimens may be unwilling to
take dry food at first which can be substituted with
live/frozen food and subsequently replaced with dry
pellets (Mishra, A. 2024). In its natural habitat
it feeds on bethnic organisms from the bottom of the
rocky streams.
Glossary
of Terms
Adipose
fin:Fleshy finlike projection
without rays, behind the rayed dorsal fin. Anal fin: The median, unpaired, ventrally
located fin that lies behind the anus, usually on
the posterior half of the fish. Barbels: Whisker-like structure on
the heads of most catfish. Caudal peduncle: The narrow part
of a fish's body to which the caudal or tail fin is
attached. Dorsal fin:
The primary rayed fin(s) on top of the body. Lateral line: A sensory line, along
the sides of the body. Pectoral fin: The paired fins just
behind the head. Pelvic fin: The paired fins, between
the pectorals and the anal fins (also referred to
as ventrals).
Etymology
Olyra:
Etymology
not explained, perhaps from Olyra, Greek for a kind
of grain (perhaps rye), or Olyra Linneaus
1759, a genus of neotropical grasses, perhaps referring
to similarity of some Olyra leaves (pointed at one
end) to the pointed tail of O. longicaudata. longicaudata:
longus, long; caudata, tailed, probably referring
to the middle rays of the tail “prolonged to
a lengthened point.
Olyra
longicaudata was described from the Khasi Hills
in Meghalaya, India (McClelland 1842). This species
is known from the Brahmaputra River drainage in India,
river drainages in Myanmar and the Mae Khlong River
drainage in western Thailand; the taxonomic status of
the eastern and western populations required further
study. The population size and trend for this species
remain unknown and this species is only known from scanty
museum records. Whilst there is also very little information
on the biology of this species and potential impacts
of threats (especially those of an anthropogenic nature)
and there is a question over the identity of the two
populations, the species is assessed as Least Concern
at present as it has an apparently wide distribution
within India and Myanmar (needs updating 2010).
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