Devario affinis (BLYTH, 1860)

SynonymsTop ↑

Perilampus affinis Blyth, 1860

Etymology

Devario: appears to be derived from a local vernacular name for the type species of the genus Cyprinus (now Devario) devario Hamilton, 1822.

affinis: from the Latin affinis, meaning ‘allied to, kindred to’, in reference to this species’ similarity to the congener Devario aequipinnatus.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Type locality is ‘Tenasserim, Myanmar’ which at time of description was used to refer to the portion of Myanmar lying to the south and east of the Ayeyarwaddy/Irrawaddy river delta, including present-day Kayah, Kayin, and Mon states, Bago Division, and possibly the southern Tanintharyi Region.

Blyth’s description paper covered fishes collected from the Sittaung River (plus a few Gangetic species) in what is currently Bago Division, but we’ve been unable to locate any modern records of D. affinis from that drainage.

Instead, fish appearing in the aquarium trade have been collected in Dawei District, Tanintharyi Region, southern Myanmar, and it appears to occur in rivers draining the western face of the Bilauktaung subrange of the Tennasserim Hills mountain range, plus the lower Salween river basin.

Habitat

Likely restricted to hill streams and upper parts of small rivers containing clear, well-oxygenated water with substrates of gravel and variably-sized rocks and some marginal or over-hanging vegetation.

Water flow, volume and turbidity are almost certainly variable depending on time of year.

Maximum Standard Length

At least 80 mm.

Aquarium SizeTop ↑

An aquarium with base dimensions of 120 ∗ 45 cm or equivalent should be the minimum considered.

Maintenance

No information regarding captive care exists but presumably it won’t prove difficult to keep in a well-maintained set-up as with related species.

It’s likely to thrive in an aquarium set up to resemble a flowing stream or river with a substrate of variably-sized, water-worn rocks, sand, fine gravel and perhaps some small boulders.

This can be further furnished with driftwood roots or branches, and 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.

Since it naturally occurs in pristine habitats it’s probably intolerant to accumulation of organic pollutants and requires more-or-less spotless water in order to thrive.

Though very fast flow is unnecessary it should also prefer a relatively high proportion of dissolved oxygen and moderate water movement.

Weekly water changes of 30-50% tank volume should be considered routine, and the tank must have a very tightly-fitting cover as all Devario spp. are accomplished jumpers.

Diet

Almost certain to prey chiefly on insects and their larvae in nature and likely to prove an unfussy feeder in captivity.

A good quality dried product can be used as the staple diet but this should be supplemented with regular meals of small live and frozen fare such as bloodworm, Daphnia, Artemia, etc., for the best colouration and conditioning.

Behaviour and CompatibilityTop ↑

Not known at this time, but unlikely to prove aggressive and should do well alongside comparably-sized fish inhabting similar environments in nature.

As with other members of the genus a group of 6 or more should be the minimum purchased.

Sexual Dimorphism

Sexually mature females should be rounder-bellied, less colourful and a little larger than males.

NotesTop ↑

This species was considered synonymous with D. aequipinnatus for a period but revalidated by Fang in 2001.

It’s poorly-known in the aquarium hobby and to date we’ve been unable to obtain diagnostic details beyond those given by Blyth in 1860.

In recent years it’s become commonplace to refer to the stripes on the body and fins of danionins as follows:

– P stripe: or ‘pigment stripe‘ is the central, dark, lateral stripe on the body which extends into the caudal-fin in some species. Stripes above it are numbered P+1, P+2, etc., and those beneath P-1, P-2, P-3.
– A stripe: the central stripe on the anal-fin; the proximal stripe (above it) is A+1 and the distal stripe (beneath) A-1.
– D stripe: The submarginal dorsal-fin stripe.

Following Fang (2003) Devario spp. are characterised by: possession of a P stripe extending onto the median caudal-fin rays; a short maxillary barbel (absent in some species); absence of the A stripe (a less distinct, relatively wide stripe is present in some species, e.g., D. acrostomus, D. annandalei, D. xyrops); a short, wide premaxillary process (cleft in the upper jaw) with a tiny apophysis (bony tubercule) touching the kinethmoid bone; infraorbital 5 not or slightly reduced.

The current genus name has only been in general use since 2003 prior to which members were considered to belong to the genus Danio.

Older, molecular, phylogenies tended to agree that the latter represented a monophyletic group consisting of two major clades; the ‘Danio devario‘ group containing the larger, deeper-bodied species and the ‘D. rerio‘ clade comprising the smaller, slimmer fish.

However in 2003 Fang Fang conducted a more detailed study based on morphological characters which included members of other related genera, and the results suggested for the first time that the genus Danio as previously considered represents a polyphyletic grouping, i.e., not all members derived from a single common ancestor.

The genus name Devario was suggested for the larger species with Danio being applied only to the smaller fish, although following Kottelat (2013) the latter should be used only for the type species, Danio dangila, with most former members placed within the revalidated genera Brachydanio and Celestichthys.

These results have largely been supported by subsequent phylogenetic analyses (e.g. Mayden et al., 2007), although Devario has still undergone a little reshuffling, particularly following Fang et al. (2009) and Kottelat (2013).

In the former study the two species previously comprising the genus Inlecypris were brought into synonymy with Devario and three species formerly included in Microrasbora were moved into the new genus Microdevario based on possession of shared synapomorphies with Devario. The existence of a monophyletic clade consisting of the genera Devario, Chela, Laubuca, Microdevario and Microrasbora was also hypothesised, a theory upheld in the more recent study by Tang et al. (2010). The genus Betadevario (Pramod et al., 2010) is also nested within this grouping and is sister to Devario and Microrasbora.

Kottelat (2013) revalidated the genus Inlecypris whilst noting that phylogenetic evidence suggests the existence of two genetic lineages within Devario. The first contains the species with prominent lateral stripes, which leaves the remaining members (D. apogon and D. chrysotaeniatus) of uncertain taxonomic placement. In addition, a number of the striped species share a colour pattern comprising a midlateral stripe on the posterior half of the body with a few bars in the anterior portion and golden patches between them. These may eventually be placed in a separate genus for which the name Parabarilius is available.

References

1. Blyth, E., 1860 - Journal of the Asiatic Society of Bengal 29(2): 138-174
   Report on some fishes received chiefly from the Sitang River and its tributary streams, Tenasserim Provinces.
2. Fang, F., 2000 - Ichthyological Research 47(1): 13-26
   Barred Danio species from the Irrawaddy River drainage (Teleostei, Cyprinidae).
3. Fang, F., 2003 - Copeia 2003(4): 714-728
   Phylogenetic Analysis of the Asian Cyprinid Genus Danio (Teleostei, Cyprinidae).
4. Fang, F. and S. O. Kullander, 2009 - Zootaxa 2164: 33-40
   Devario xyrops, a new speceis of danionine fish from south-western Myanmar (Teleostei: Cyprinidae).
5. Fang, F., M. Norén, T. Y. Liao, M. Källersjö and S. O. Kullander, 2009 - Zoologica Scripta 38(1): 1-20
   Molecular phylogenetic interrelationships of the south Asian cyprinid genera Danio, Devario and Microrasbora (Teleostei, Cyprinidae, Danioninae).
6. Kottelat, M., 2013 - The Raffles Bulletin of Zoology Supplement 27: 1-663
   The fishes of the inland waters of southeast Asia: a catalogue and core bibiography of the fishes known to occur in freshwaters, mangroves and estuaries.
7. Mayden, R. L., K. L. Tang, K. W. Conway, J. Freyhof, S. Chamberlain, M. Haskins, L. Schneider, M. Sudkamp, R. M. Wood, M. Agnew, A. Bufalino, Z. Sulaiman, M. Miya, K. Saitoh, S. He, 2007 - Journal of Experimental Zoology, Molecular Development and Evolution 308B: 642-654
   Phylogenetic relationships of Danio within the order Cypriniformes: a framework for comparative and evolutionary studies of a model species.
8. Pramod, P. K., F. Fang, K. Rema Devi, T.-Y. Liao, T. J. Indra, K. S. Jameela Beevi and S. O. Kullander, 2010 - Zootaxa 2519: 31-47
   Betadevario ramachandrani a new danionine genus and species from the Western Ghats of India (Teleostei: Cyprinidae: Danioninae).
9. Tang, K. L., M. K. Agnew, W. J. Chen., M. V. Hirt, T. Sado, L. M. Schneider, J. Freyhof, Z. Sulaiman, E. Swartz, C. Vidthayanon, M. Miya, K. Saitoh, A. M. Simons, R. M. Wood and R. L. Mayden, 2010 - Molecular Phylogenetics and Evolution 57(1): 189-214
   Systematics of the subfamily Danioninae (Teleostei: Cypriniformes: Cyprinidae).