Biometric analysis of the flat needlefish Ablennes hians (Valenciennes, 1846) (Pisces: Belonidae) in the south-eastern Arabian Sea

The study was aimed to investigate the relationship between various morphometric measurements and meristic counts and to establish the length-weight relationships (LWRs) and length-length relationships (LLRs) of flat needlefish Ablennes hians (Valenciennes, 1846) that were collected from longline fisheries in the south-eastern Arabian Sea between October 2015 and August 2017. Twenty-two morphometric measurements and four meristic counts of 173 specimens were examined for biometric analysis, and 350 specimens (45-122 cm TL, 90-2585 g TW) were analyzed for studying LWRs. Morphometric variables showed a significant correlation between the variables with the highest observed correlation between SL, FL and TL (r > 0.99). The descriptive statistics for all the meristic counts were found within the range provided by the earlier authors. A differential relative growth was observed across morphometric characters. Strong positive allometry was recorded for pectoral fin length, the height of dorsal and anal fin and pre-ventral length, whereas pronounced negative allometry was evident in case of morphometric variables from the head region. The LWRs showed similar growth pattern for male (b = 3.447) and female (b = 3.299) individuals. Therefore, the LWR was expressed for pooled data as W = 0.000321L(3)(.)(312) (R-2 = 0.929,p < 0.001).