A review of the South Asian catfish genus Hara recognizes eight valid species.
In the revision, which is published in the most recent issue of the journal Revue Suisse de Zoologie, Heok Hee Ng and Maurice Kottelat recognize eight valid species of Hara, of which four are described as new: H. filamentosa, H. hara, H. horai, H. jerdoni, H. longissima, H. mesembrina, H. minuscula, and H. spinulus.
The authors examined specimens from Bangladesh, India, Myanmar and Thailand and recognised four valid species (H. filamentosa H. hara, H. horai and H. jerdoni) in addition to describing four new species (H. longissima, H. mesembrina, H. minuscula, and H. spinulus).
The eight species are distinguished from each other primarily by body proportions.
Hara filamentosaHara filamentosa is known from the the Ataran, Salween and Sittang river drainages in southern Myanmar and western Thailand.
It is distinguished from other members of the genus except H. mesembrina and H. longissima in sometimes having a filamentous extension to the first principal ray of the upper caudal-fin lobe; it is also distinguished from other members of the genus except H. hara and H. longissima in having a posterior process on coracoid reaching to midway of distance between bases of pectoral spine and first pelvic-fin ray.
It differs from H. longissima in having a shorter and deeper caudal peduncle and deeper body.
Hara maesotensis is a junior synonym of this species, which reaches a maximum size of 67 mm SL.
Hara haraHara hara is known from the Ganges and Brahmaputra river drainages in India and Bangladesh.
It is distinguished from other members of the genus in having serrations on the anterior edge of the pectoral spine.
Hara saharsai and Hara serrata are junior synonyms of this species, which reaches a maximum size of 50 mm SL.
Hara horaiHara horai is known from the Brahmaputra River drainage in northeast India.
It is distinguished from other members of the genus except for H. jerdoni in having a longer head.
It differs from H. jerdoni in having shorter pectoral spine, more soft pectoral-fin rays, more vertebrae, the supraoccipital spine not reaching the anterior nuchal plate and a deeply forked caudal fin.
It is the largest member of the genus, reaching a size of 85 mm SL.
Hara jerdoniHara jerdoni is known from the Ganges and Brahmaputra river drainages in Bangaldesh and India.
It is distinguished from other members of the genus in having a longer pectoral spine, fewer vertebrae, an emarginate caudal fin and a posterior process on coracoid reaching to four fifths of distance between bases of pectoral spine and first pelvic-fin ray.
It is the smallest member of the genus, reaching a maximum size of 20 mm SL.
Hara longissimaHara longissima, named after the relatively long caudal peduncle of this species (the Latin longissimus means the longest), is known from the Irrawaddy river drainage in central Myanmar.
It is distinguished from other members of the genus in having a longer caudal peduncle and from other members of the genus except H. filamentosa and H. mesembrina in having a filamentous extension of the first principal ray of the upper caudal-fin lobe.
It reaches a maximum size of 55 mm SL.
Hara mesembrinaHara mesembrina is known from the short coastal rivers draining westwards into the Andaman Sea on the Isthmus of Kra in southern Thailand, representing the southernmost record of this genus.
It can be distinguished from other members of the genus except H. filamentosa and H. longissima in having a filamentous extension to the first principal ray of the upper caudal-fin lobe.
It differs from H. filamentosa in having a posterior process on coracoid reaching to two thirds of distance between bases of pectoral spine and first pelvic-fin ray and a longer caudal peduncle, and from H. longissima in having a shorter caudal peduncle, larger eye and posterior process on coracoid reaching to two thirds of distance between bases of pectoral spine and first pelvic-fin ray.
It reaches a maximum size of 56 mm SL, and the specific name comes from the Greek mesembrinos, meaning southern, in reference to the distribution of this species.
Hara minusculaHara minuscula is known from the Sittang River drainage in southern Myanmar.
The name of this species comes from the Latin minusculus, meaning rather small, referring to the small size of this species.
It can be distinguished from other members of the genus except H. jerdoni in having a posterior process on coracoid reaching to three quarters of distance between bases of pectoral spine and first pelvic-fin ray, fewer soft pectoral-fin rays and the supraoccipital spine reaching the anterior nuchal plate.
It differs from H. jerdoni in having a shorter pectoral spine and more vertebrae. This relatively small species reaches a maximum size of 30 mm SL.
Hara spinulusHara spinulus is known from the Baw Di Chaung River drainage in southwestern Myanmar.
It can be distinguished from other members of the genus except H. minuscula in having a shorter dorsal spine (the specific name comes from the diminutive form of the Latin spina, meaning thorn, and refers to the short dorsal spine of this species) .
It differs from H. minuscula in having a deeper caudal peduncle, posterior process on coracoid reaching to two thirds of distance between bases of pectoral spine and first pelvic-fin ray, more soft pectoral-fin rays and the supraoccipital spine not reaching the anterior nuchal plate.
This species reaches a maximum size of 50 mm SL.
For more information, see the paper: Ng, HH and M Kottelat (2007) A review of the catfish genus Hara, with the description of four new species (Siluriformes: Erethistidae). Revue Suisse de Zoology 107.