Morphological variation in an anopthalmic specimen of Sperata seenghala (Sykes, 1839) from Brahmaputra River, Assam, India

The present investigation reports the variation observed in morphological traits of an anopthalmic specimen of Sperata seenghala (Sykes, 1839) (168.9 mm in standard length) from Assam. Thirty morphometric and six meristic characters of the abnormal specimen were studied and compared with normal specimens to observe variation in the morpho-meristic traits, if any. The proportionate pre-pectoral length (28.5 mm), length of dorsal fin base (15.0 mm), pelvic fin length (15.5 mm), distance between urino-genital openings and anal fin base (14.0 mm) and body depth at pectoral fin base (12.0 mm) of the abnormal specimen was found to be higher compared to that of the normal specimens (23.8 – 26.5 mm; 12.2 – 14.1 mm; 11.1 – 14.7 mm; 10.9 – 12.4 mm and 8.9 – 9.9 mm, respectively); while the dorsal to adiposedistance (12.8 mm) and body width at cleithrum (41.5 mm) was lower than the normal specimens (13.7 – 16.7 mm and 44.0 – 50.0 mm, respectively). No marked variation was observed in the meristic characters. Pollution due to urban runoff, sewage discharge and oil spill from inland water transport facilities adversely affecting the river water quality could be the reason for such deformity. The overall growth performance of the fish does not seem to be affected by these anomalies

A record of anopthalmia in Mystus tengara (Hamilton, 1822) from Assam

An abnormal case of anopthalmia in a striped catfish Mystus tengara (66.8 mm in standard length) from Assam is reported in this communication. Thirty eight morphological characters of the abnormal specimen were also studied and compared with normal specimens to observe variation in the morpho-meristic traits, if any. In the abnormal specimen, the proportionate height of the dorsal fin (31.1 mm) and nasal barbel length (75.9 mm) was found to be higher compared to that of the normal specimens (21.6 – 26.5 mm and 47.9 – 72.5 mm, respectively). While the body depth of anus was higher in case of normal specimens (19.1 – 29.2 mm) compared to abnormal specimen (14.5 mm). However, no marked variation was observed in meristic characters. This anomaly does not seem to have affected morphological aspects. Factors like weed infestation, pesticide and herbicide application adversely affecting the habitat is believed to be the cause of such deformity. The abnormality does not seem to have affected the overall growth of the fish

Variation in morphometric and meristic traits of Aspidoparia morar from Brahmaputra and Barak Rivers of Assam, India

The minor carp, Aspidoparia morar is a benthopelagic fish belonging to the sub-family Danioninae under the family Cyprinidae. It has emerged as the single most dominant species in the river Brahmaputra in Assam. In the present study, 240 specimens were collected from Guwahati and Tezpur in the Brahmaputra River and Silchar in the Barak River to investigate the morphometric and meristic variation among the populations. For this a total of 20 morphometric traits and 11 meristic traits were studied. The mean lengths for most of the morphometric traits were higher for the Barak River except eye diameter, inter orbital length and anal fin length which were significantly higher on the Brahmaputra River, while the post orbital length and pelvic fin length were found to be almost equal. The regressions of standard length with all the morphometric traits except pelvic fin length, pelvic fin base, pectoral fin length, dorsal fin length, anal fin length, pre orbital length, post orbital length, inter orbital length and eye diameter showed significant variation between the rivers. Two meristic traits viz. branched rays in anal fin and gill rakers on the first gill arch also showed significant variation in the samples of the rivers

Indigenous techniques of catching the mud eel, <i style="mso-bidi-font-style:normal">Monopterus cuchia</i> (Ham.) in Goalpara district, Assam

109-115Fishing techniques for catching the mud eel, Monopterus cuchia (Ham.) in Goalpara district, Assam was investigated during 2007-10 during the course of a base line survey conducted by the KVK Goalpara, Assam. The complexities of its habitat, behavior and life history characteristics, makes it difficult to catch the fish. Documentation on the fishing methods for catching the mud eel is scanty. This paper is an attempt to record the different technique employed traditionally by the ethnic communities of the district to catch the mud eel based on the information collected during the course of survey. The results revealed use of different wounding gears, ichthyotoxic plants, handline and traps. Wounding gears included spear, knives and sickle. Among plants, Derris elliptica (Wall.) Benth. and Milletia pachycarpa Benth. were used. Spindle shaped and cubical traps are commonly used by the common folks. Other method includes bunding and digging, and light fishing