Diet and feeding ecology of black-barred halfbeak Hemiramphus far (Forsskal, 1775) (Hemiramphidae) from Karachi coast of Pakistan

Abstract

To describe the diet and feeding ecology of Hemiramphus far (H. far) through investigating the stomach contents. Methods: Sampling of total 430 individuals of H. far was carried out from commercial catches landed at West Wharf fish harbor of Karachi coast, Pakistan during January-December 2010. The total length and weight of each individual were recorded. Samples were parted into Group 1 (15-20 cm, n = 240) and Group 2 (21-26 cm, n = 190), to estimate changes in diet with fish size. To remove alimentary canal, fishes were dissected and kept into 10% formalin. Then gut contents were examined under a light microscope for each intestine. Stomach fullness as well as dietary composition was ascertained from gut contents. Examination and analyses were conducted using frequency of occurrence and numerical method. Results: The examination confirmed 47.67% stomach as empty. Furthermore, our study revealed that the diet of H. far consists of fishes, isopods, ostracods, Daphnia, shells, algae, unidentified plants and animal materials. This study proved that H. far is an omnivorous fish feeding on fishes, isopods, shells, algae and plant and animal originated different food items. According to the Schoener overlap index, there was no significant difference in feeding of the two length groups of H. far (C = 0.833). In addition, the Shannon-Wiener index presented that in Group 1, the prey diversity of the halfbeak was lower (H = 0.90) than that of Group 2 (H = 1.02). Conclusions: The findings of the present study would be very effective for sustainable management of black-barred halfbeak fishery in the Karachi coast of Pakistan and the surrounding ecosystems.

Predation risk, foraging and reproduction of an insectivore fish species associated with two estuarine habitats

“…The pronounced foraging tactic of common halfbeak to target prey (Hymnoptera) is similar the registered by Delabie et al (2006), and is thus presumed to be related to the presence of insects on the seawater surface. This behaviour has been registered by other Hemiramphidae across different habitats (Tabassum et al 2017;Abidin et al 2019), where insects were ingested in proximity to oating objects or sucked from the water surface (Kanai et al 2017).…”

Length-weight relationship, condition factor, and reproductive aspects of Lutke's halfbeak Hemiramphus lutkei (Valenciennes, 1847) from Seram Sea, Maluku, Indonesia

“…The lowest Kn values for male fish (0.94) were observed in November, January, and February, while the lowest Kn values for female fish (0.92) occurred in September. H. lutkei from the Seram Sea Maluku has a slightly different Kn value from H. lutkei from the coast of Nain Island, North Minahasa male 0.98±0.06 and females 1.03±0.07, while H. lutkei from the Karachi Coast, Pakistan, Kn value between 0.844 and 1.250 (Tabassum et al 2017b). Kn was classified into <0.95 for fair, 0.95-1.05 for good, and >1.05 for very good.…”

The ontogenic study of early life stages of culture-bred Nomorhamphus sp. (Zenarchopteridae) from Lindu, Central Sulawesi

“…In general, juvenile fish feed more on zooplankton and small gastropods, while larger juveniles feed land insects, such as ants and flies (Kanai et al, 2017). In another halfbeak species, Hemiramphus far, is known as an omnivorous fish, as it feeds on fish, isopods, ostracods, Daphnia, shellfish, algae, and unidentified parts of plants and animals (Tabassum et al, 2017). The superior jaw shape of the Nomorhamphus, where the lower jaw is longer than the upper jaw, indicates that this fish is a type of surface feeding, as seen in Z. dunckeri (Hirota et al, 2015), H. far (Tabassum et al, 2017), and other Nomorhamphus as endemic species in Sulawesi (Kraemer et al, 2019a;Kobayashi et al, 2020).…”

“…In another halfbeak species, Hemiramphus far, is known as an omnivorous fish, as it feeds on fish, isopods, ostracods, Daphnia, shellfish, algae, and unidentified parts of plants and animals (Tabassum et al, 2017). The superior jaw shape of the Nomorhamphus, where the lower jaw is longer than the upper jaw, indicates that this fish is a type of surface feeding, as seen in Z. dunckeri (Hirota et al, 2015), H. far (Tabassum et al, 2017), and other Nomorhamphus as endemic species in Sulawesi (Kraemer et al, 2019a;Kobayashi et al, 2020). The success of maintaining the early life stages in this study provides important information for the culture management of Nomorhamphus sp.…”