Volume 27, Issue 1 – 22 March 2021
Tyson R. Roberts: Glyptothorax pedunculatus, a New Species of Sumatran Sisorid Catfish with Slender Caudal Peduncle and Simple Thoracic Adhesive Organ, pp. 1-4
Glyptothorax pedunculatus new species is described from the Musi River basin in central Sumatra. It differs from all other species in the genus by its more slender caudal peduncle and by its thoracic adhesive organ lacking a median groove and with nearly straight striae. Ten species of Glyptothorax are now known from Sumatra.
Glyptothorax pedunculatus, holotype, CAS 247199, 64.5 mm, gravid female, lateral view, Sumatra, Musi Basin. Photo by T. R. Roberts.
Dalton Tavares Bressane Nielsen and Renato Pastor Veiga: Anablepsoides origuelai, a new species of the Anablepsoides ornatus species group (Cyprinodontiformes: Rivulidae) from Rio Tapajós drainage, Amazon basin, Brazil, pp. 5-10
Anablepsoides origuelai, new species, is described from the Rio Tapajós drainage, near at its mouth at the Amazon River, Brazil. It was found in lentic portions of a tributary of rio Tapajós. The new species is a member of the Anablepsoides ornatus species group, which includes another five species, all occurring in the central portion of the Amazon basin. The new species differs from the other species of the Anablepsoides ornatus species group by presenting a similar orange color pattern in the dorsal and ventral portions of the caudal fin, less rays in the caudal fin and a lower number of vertebrae. The new species seems to be more closely related to A. ornatus, with which it shares a pattern of red dots distributed irregularly across the sides of the body.
Anablepsoides origuelai, ZUEC 17329, male, holotype, 25.6 mm SL, Brazil, Amazonas, Santarém. Photo by D. Nielsen.
Gerald R. Allen: Gobiodon howsoni, a new species of coral reef fish (Gobiidae: Teleostei) from Rowley Shoals, Western Australia, pp. 11-20
A new species of gobiid fish, Gobiodon howsoni, is described from north-western Australia on the basis of 15 specimens, 15.8-27.1 mm SL. It is separable from congenerics on the basis of its unique live colour pattern: semitranslucent greyish with a bifurcate white stripe straddling the spinal column, a narrow brown stripe on the back extending from the side of the nape to the caudal peduncle, and a wider brown stripe on the ventral portion of the body extending from the pectoral-fin axil to the caudal peduncle. Some smaller individuals (< about 20 mm SL) possess a strong yellow tint on the head and body, and lack the dorsal-most brown stripe on the side. The new species also differs from most members of the genus in having a relatively low number of pectoral-fin rays (15-17, usually 16). Other features include: dorsal-fin rays VI+I,10, anal-fin rays I,9 (rarely I,8), branched caudal-fin rays usually 15 (occasionally 14, especially specimens < 16 mm SL), anterior dentary with a single enlarged canine posterior to the main band of smaller teeth, and the aperture of the genital papilla reaching or nearly reaching the anal-fin origin when adpressed. The species is most similar to and sympatric with G. okinawae, but differs in usually having 15 versus 13 branched caudal rays, one versus two enlarged canines on the posterior dentary, the genital papilla usually reaching the anal-fin origin versus falling well short of the anal fin, and possessing 1-2 brown stripes on the body versus a uniform bright yellow colour.
Gobiodon howsoni, underwater photo of adult, approximately 25 mm SL, Rowley Shoals, Western Australia. Photo by G. R. Allen.
Tyson R. Roberts, Priyankar Chakraborty, Kranti Yardi, and Prasun Mukherjee: Oryzias andrewi, new species of slender ricefish from Bengal, India, related to the highly specialized western indian coastal Horaichthys setnai Kulkarini 1940 (Cyprinodontiformes, Adrianichthyidae), pp. 21-35
Oryzias andrewi, the first known elongate or slender (as opposed to deeper-body) Indian species of the rice-fish genus Oryzias is described based on specimens collected in widely separated localities in the Ganges basin in Assam and Bengal. It is more closely related than any previously known species to the extremely specialized and even more slender adrianichthyid Horaichthys setnai, widely and continuously distributed in estuarine habitats and fresh water habitats along nearly the entire coast of the Western Ghats in the Indian subcontinent. O. andrewi and H. setnai agree in having a well-defined black stripe parallel to the anal fin base (not the same as a thinner black line over the anal fin distal pterygiophores), in having only 4 -5 branchiostegal rays (6 in some other Oryzias), and in having all or nearly all of the rays in the anal fin simple (not branched), a condition also found in many other species of Oryzias. The most substantial characters distinguishing Horaichthys from our new species of slender Oryzias are its more highly specialized reproductive structures, increased number of vertebrae, and unusually numerous enlarged teeth on distal end of premaxilla in males.
Oryzias andrewi n. sp. live specimen collected with holotype.
Index of aqua Vol. 26 (1-4), p. 36