Mesonoemacheilus petrubanarescui

Mesonoemacheilus: from the Greek meso, meaning half, nema, meaning thread or filament, and cheilos, meaning 'lip', in reference to the relatively less-furrowed lip in members compared to that in Nemacheilus spp.

petrubanarescui: named for Dr. Petru M. Bănărescu of the Institute of Biology, Bucharest, Romania, 'in recognition of his outstanding contribution to our knowledge of the systematics of fishes of the family Cobitidae'.

Type locality is 'Netravati River, Dharmasthala, Karnataka State, India', with the species subsequently recorded from the Kabini (aka Kabani) River basin and it may be endemic to these two drainages, with all known localities within the Western Ghats mountain range.

While the Netraviti flows through Karnataka in its entirety before emptying into the Arabian Sea just south of the city of Mangalore, the Kabini is a principal tributary of the Cauvery watershed arising in Kerala state and flowing eastward until its confluence with the Cauvery at Tirumakudala Narasipura.

It's unclear if M. petrubanarescui occurs elsewhere in the Cauvery basin but it has been recorded in the Kumaradhara drainage, a major tributary of the Netravati.

Inhabits clear, well-oxygenated, headwater streams and minor rivers.

These are often shaded by surrounding forest cover with the substrate normally composed of coarse sand, gravel, rocks and boulders covered with an epilithic layer of algae, diatoms plus other microorganisms and detritus.

Aquatic plants usually absent, though Lagenandra and Blyxa spp. have been observed at some lower-gradient habitats.

Flow rate and turbidity vary somewhat depending on the time of year with both increasing dramatically during the annual monsoon season which occurs between June and September.

An aquarium with a base measuring at least 60 ∗ 30 cm24 ∗ 12 in is recommended.

Not difficult to maintain under the correct conditions; we strongly recommend keeping it in a tank designed to resemble a flowing stream or river with a substrate of variably-sized rocks, sand, fine gravel, and some water-worn boulders.

This can be further furnished with driftwood branches arranged to form a network of nooks, crannies, and shaded spots, thus providing broken lines of sight.

While the majority of aquatic plants will fail to thrive in such surroundings hardy types such as Microsorum, Bolbitis, or Anubias spp. can be grown attached to the décor.

Though torrent-like conditions are unnecessary it does best if there is a high proportion of dissolved oxygen and some water movement in the tank meaning power filter(s), additional powerhead(s), or airstone(s) should be employed as necessary.

Like many fishes that naturally inhabit running water it's intolerant to accumulation of organic pollutants and requires spotless water in order to thrive, meaning weekly water changes of 30-50% tank volume should be considered routine.

Mesonoemacheilus species are omnivorous although the bulk of their diet consists of small insects, worms, crustaceans and other zooplankton with only relatively small amounts of plant matter consumed.

In the aquarium they will accept dried foods of a suitable size but should not be fed these exclusively.

Daily meals of small live and frozen fare such as Daphnia, Artemia, bloodworm, etc. will result in the best colouration and condition.

Fishes which inhabit similar biotopes in nature, especially small, open-water dwelling cyprinids constitute the best options, and one or two schools can make a visible difference to the confidence of this naturally reclusive loach.

Other possibilities include rheophilic loaches from genera such as Pseudogastromyzon, Beaufortia and Sewellia (avoid the more delicate genera, e.g., Gastromyzon) plus benthic cyprinds like Crossocheilus and Garra species.

Similarly-shaped relatives such as Nemacheilus, Acanthocobitis and Schistura spp. are not really recommended although a combination may work in larger aquaria, while sedate bottom-dwellers such as Corydoras spp. catfishes are best omitted entirely.

This species is relatively peaceful with conspecifics and seems to appreciate being maintained in a group. The purchase of four or more specimens is therefore highly recommended.

Adult females are likely to grow slightly larger and be rounder-bellied than males when gravid.

Unrecorded.

We're unsure if this species has ever been traded in the aquarium hobby outside of India but there may be a chance of finding the occasional specimen mixed in with shipments of M. guentheri or M. triangularis, the only members of the genus exported with any regularity.

Following the identification key of Rema Devi and Indra (2002) it can be distinguished from congeners by a combination of characters as follows: lateral line incomplete, ending above anal-fin origin; 7-8 dark, saddle-shaped markings on the dorsal surface; flanks with varying number of broken bars, appearing narrower anteriorly.

With regard to the remaining members of the genus, only M. guentheri is regularly exported for the aquarium trade and is easily told apart since its body patterning comprises rows of yellowish, dark-edged spots, as does that of M. herrei.

M. petrubanarescui has dark body stripes, M. menoni a reticulated pattern of dark bands and blotches, M. pambarensis more branched dorsal-fin rays (8-10, usually 9, vs. 7-8 in M. guentheri) plus an elongate body the depth of which fits more than 5.5 times into the SL, M. pulchellus also has more branched dorsal-fin rays (always 10) and M. remadevii lacks dark markings in the fins.

All Mesonoemacheilus spp. are endemic to rivers draining the Western Ghats and the genus is separated from the closely-related Nemacheilus by members possessing two pairs of rostral barbels which are confluent at their bases vs. rostral barbels present but not confluent.

In addition, the lips are usually less deeply-furrowed in Mesonoemacheilus than Nemacheilus spp. while Bãnãrescu and Nalbant (1995) noted that Mesonoemacheilus is the only nemacheilid genus exhibiting a greater degree of brownish than whitish colouration.

According to Rema Devi and Indra (2002) Schistura savona from northern India uniquely shares both this feature plus possession of confluent rostral barbels and this may warrant further study, though it appears that this suggestion has not been followed to date.

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