Acanthocobitis sinuata (DAY, 1870)

SynonymsTop ↑

Nemacheilus sinatus Day, 1870

Etymology

Acanthocobitis: from the Greek ákantha (Gr. ἄκανθα), meaning ‘thorn’, and kobitis (Gr. κωβῖτις), the ancient Greek name for small fishes that bury in the bottom and/or are like a gudgeon or goby (first applied to loaches by Rondelet in 1555).

sinuata: from the Latin sinuatus, meaning ‘bent’, in reference to the sinuous, black, >-shaped markings on the caudal-fin of this species.

Classification

Order: Cypriniformes Family: Nemacheilidae

Distribution

Described from ‘Wynaad’, which corresponds to Wayanad district, Kerala state in the southwest of the country, and probably the Cauvery River system.

This species appears to be widespread in drainages of the Indian peninsula located south of, but not including, the Krishna watershed.

Habitat

Given the extent of its distribution habitats are likely to vary to some extent and in some areas are almost certainly seasonal in nature, e.g., swelling in volume and flowing more rapidly during the annual monsoons.

However in general it shows a preference for stretches of streams and small rivers where leaf litter and other debris collects over substrates of open sand, mixed cobbles, rocks, and boulders.

At one habitat in the Western Ghats mountains it was collected from a tributary river comprising faster, shallow stretches with wider, deeper sections between. Substrate appears composed of gravel, cobbles, rocks, boulders and exposed bedrock and marginal vegetation is abundant.

Aquatic plants recorded were Cryptocoryne retrospiralis, Utricularia, and Lavendra spp., with sympatric fishes including Lepidocephalichthys thermalis, Mesonoemacheilus guentheri, Schistura semiarmatus, S. cf. nilgiriensis, plus at least one unidentified Schistura sp.

Maximum Standard Length

55 – 75 mm.

Aquarium SizeTop ↑

Base dimensions in excess of 75 ∗ 30 cm are sufficient.

Maintenance

Should do well in most well-maintained aquaria  if plenty of hiding places are provided, and should not harm softer-leaved plants.

However we recommend keeping it in a set-up designed to resemble a slow-moving or marginal section of a stream or river with a sandy substrate and perhaps a few water-worn boulders.

This can be further decorated with driftwood roots and branches arranged to form some shaded spots, plus a few handfuls of dried leaves of a suitable type.

Aquatic plants such as Microsorum, Bolbitis or Anubias spp. can be grown attached to the décor and bright lighting will promote the growth of aufwuchs which will add to the natural feel.

In this kind of environment the fish will show more natural behaviour and can be maintained alongside other species that enjoy similar conditions.

Although a high level of water movement isn’t essential it should also thrive in a mature hill stream-type set-up with a rocky aquascape.

Water Conditions

Temperature: 20 – 26 °C

pH: 6.0 – 7.5

Hardness: 18 – 215 ppm

Diet

Probably a micropredator feeding on insect larvae and suchlike in nature.

In the aquarium it will accept sinking dried foods but should also be offered regular meals of small live and frozen fare such as Daphnia, Artemia, bloodworm, etc. A varied diet is the key to maintaining it in the best of health.

Behaviour and CompatibilityTop ↑

Generally non-aggressive and can be maintained alongside many of the more popular species in the hobby although our preference would be to select fishes from from one of its native countries or rivers.

Peaceful, similarly-sized or smaller, schooling cyprinids are excellent choices as are other loaches such as Lepidocephalichthys and some Nemacheilus spp.

In a hill stream-style set-up it can also be housed with rheophilic loaches from genera such as Gastromyzon, Pseudogastromyzon, Beaufortia and Sewellia spp. but more aggressive nemacheilids, e.g., many Schistura spp. are best avoided.

Sexual Dimorphism

Adult males should be noticeably slimmer than females.

Reproduction

Unrecorded.

NotesTop ↑

A. sinuata is currently considered a synonym of A. mooreh by most authorities.

This appears attributable to a lack of recent study since the two differ in distribution plus number of dorsal-fin rays (2-3/9-10 in A. mooreh vs. 2/8-9 in A. sinuata) and some aspects of colour pattern.

Both possess a reduced lateral line ending around the dorsal-fin which in the similar-looking A. botia is complete or terminates above the anal-fin, and we include them here as per Grant (2008) as they are apparently in the process of being revalidated (R. Kumar, pers. comm.).

According to Kottelat (1990) the chief distinguishing characters for the genus are: possession of 9-18½ branched dorsal-fin rays; colour pattern without black basal caudal bar, but with an ocellus at upper base of caudal-fin; upper lip withor without several rows of papillae; lower lip with a broad median interruption and a widened, papillated padon each side.

Grant (2007) considered Acanthocobitis longipinnis, the type species of Acanthocobitis, to be a junior synonym of A. pavonacea and erected the subgenus Paracanthocobitis to include all other species since he regarded A. pavonacea to be taxonomically unique. 

Kottelat (2012a) remarked that the identity of A. longipinnis requires verification and later (Kottelat, 2012b) classed Paracanthocobitis as a questionable synonym of Acanthocobitis.

The family Nemacheilidae is widely-distributed across most of Eurasia with the Indian subcontinent, Southeast Asia and China representing particular centres of species diversity.

References

1. Day, F., 1870 - Proceedings of the Zoological Society of London 1870 (pt 2): 369-374
   Notes on some fishes from the western coast of India.
2. Grant, S., 2007 - Ichthyofile No. 2: 1-9
   A new subgenus of Acanthocobitis Peters, 1861 (Teleostei: Nemacheilidae).
3. Grant, S., 2008 - BSSW-Report 20(3): 49-52
   Schmerlen der Gattung Acanthocobitis Peters, 1861.
4. Kottelat, M., 1990 - Verlag Dr. Friedrich Pfeil, München, Germany: 1-262
   Indochinese nemacheilines. A revision of nemacheiline loaches (Pisces: Cypriniformes) of Thailand, Burma, Laos, Cambodia and southern Viet Nam.
5. Kottelat, M., 2012a - Zootaxa 3327: 45-52
   Acanthocobitis pictilis, a new species of loach from Myanmar and Thailand (Teleostei: Nemacheilidae).
6. Kottelat, M., 2012b - Raffles Bulletin of Zoology Supplement 26: 1-199
   Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei).
7. Sykes, W. H., 1839 - Proceedings of the Zoological Society of London 1838 (pt 6): 157-165
   On the fishes of the Deccan.
8. Tang, Q., H. Liu, R. Mayden and B. Xiong, 2006 - Molecular Phylogenetics and Evolution 39(2): 347-357
   Comparison of evolutionary rates in the mitochondrial DNA cytochrome b gene and control region and their implications for phylogeny of the Cobitoidea (Teleostei: Cypriniformes).