Monday, December 18, 2023

[Ichthyology • 2023] Physoschistura mango • A New miniature Species of Loach (Cypriniformes: Nemacheilidae) from Myanmar


  Physoschistura mango
Conway & Kottelat, 2023
 
RAFFLES BULLETIN OF ZOOLOGY. 71

Abstract
 Physoschistura mango, new species, is described from Shan State, Myanmar. It is distinguished from congeners by having an extremely short and incomplete lateral-line canal on the body, with only 5–6 pores; several reductions in the cephalic lateral-line canal system; and by features of the colour pattern, including a dark black to brown horizontal stripe along body side combined with a bright orange-reddish background colour in mature males. With a maximum recorded length of 23.4 mm SL, it represents one of the smallest members of the family Nemacheilidae. 

Keywords. Cobitoidea, Shan State, scanning electron microscopy, miniaturisation

 Physoschistura mango, aquarium trade;
 A, TCWC 20684.01, male, 21.7 mm SL; B, female, not preserved, not measured.

Physoschistura mango, new species

Diagnosis. Physoschistura mango is distinguished from congeners by features of the adult sexually dichromatic colour pattern, comprising a solid dark brown to black horizontal stripe along body side (distinct in mature males only), and a series of small spots or irregular markings in females (vs. colour pattern not known to be sexually dichromatic, comprising a series of vertical bars, most obvious on posterior half of body), and by having a shorter lateral-line canal on the body (5–6 pores vs. 5–10 in Ph. brunneana, 29 in Ph. raoi, 56–57 in Ph. rivulicola, 16–37 in “Ph.” pseudobrunneana). It is further distinguished by a number of reductive features of the cephalic lateral-line canal system, including a shorter infraorbital canal, with 5–7 pores, restricted to a short series of ossicles associated with the ventral edge of the lachrymal (vs. ...

Etymology. Mango, the tree Mangifera indica in reference to the orange-yellow flesh of its fruit. A noun in apposition.

 
  Kevin W. Conway and Maurice Kottelat. 2023. Physoschistura mango, A New miniature Species of Loach from Myanmar (Teleostei: Nemacheilidae). RAFFLES BULLETIN OF ZOOLOGY. 71; 681–701.