Biodiversity aspects of Common Torpedo (Torpedo torpedo) in by-catch in Sidi Sha’ab Harbour, Tripoli, Libya

Document Type : Research paper

Authors

Department of Zoology, Faculty of Science, Omar Al-Mukhtar University, Al-Bayda, Libya

Abstract

Forty-four specimens of the common torpedo (Torpedo torpedo) were collected from the discarded catch of long-line boat’s haul from Sidi Sha’ab harbor of Tripoli (May 2016) and used for establishing biodiversity and morphometric traits of the fish. The specimens ranged in size from 13.3 to 68.2 cm and in total weight from 92.61 to 989.25 g. The results revealed that the value of the constant b of the length-weight relationship was 1.9064 that indicated negative allometric growth (b< 3). The condition factors of Kf and Kc decreased progressively from 2.54 and 1.82 in the smallest fish size group (17.2 cm) to the largest one (67.5 cm) which recorded a rare value of (Kf = 0.32 and Kc = 0.25), respectively. The length-frequency distribution indicated that the youngest size-group (17.2 cm) peaked at a quarter of the studied samples. Biodiversity and Morphometric traits of the torpedo were related to total length as percentage ratios. Disk length and diameter were larger in females (48.6 and 43.0%) than in males (47.4 and 41.2%).

Graphical Abstract

Biodiversity aspects of Common Torpedo (Torpedo torpedo) in by-catch in Sidi Sha’ab Harbour, Tripoli, Libya

Highlights

  • The Mediterranean Sea is known to encompass a high diversity of important habitats threatened nowadays.
  • In Libya, fish are essential component of coast, which constitutes 36% of the Arabic Mediterranean coasts.
  • The present study is of the first studies in the biology of elasmobranches in Libya.
  • More studies are required to create good database for elasmobranches in this region.

Keywords

Main Subjects


Başusta, N., Demirhan, S.A., Çiçek, E., Başusta, A., 2017. Comparison of staining techniques for age determination of some Chondrichthyan species. Turk. J. Fish. Aquat. Sci. 17(1), 41-49.
Betts, J., Young, R.P., Hilton‐Taylor, C., Hoffmann, M., Rodríguez, J.P., Stuart, S.N., Milner‐Gulland, E.J. 2019. A framework for evaluating the impact of the IUCN Red List of threatened species. Biol. Conserv. 1-27.
Borges, T.C., Olim, S., Erzini, K., 2003. Weight-length relationship for fish species discarded in commercial fisheries of the Algarve (southern Portugal). J. Appl. Ichthyol. 19(6), 394-396.    
Bradai, M.N., Quignard, J.P., Bouain, A., Jarboui, O., Ouannes-Ghorbel, A., Ben Abdallah, L., Zaouali, J., Ben Salem, S., 2004. Exotic and exotic fish fauna of Tunisian coasts: census and biogeography. Cybium. 28(4), 315-328. ISSN: 03990974
Buzaid, E.M.K., El-Mor, M.E.E., 2015. Feeding Habits of the Copper Shark, Carcharhinus brachyurus (Günther, 1870) from Ain El-Ghazala Lagoon, Eastern Libya during the Period from February till June 2013. J. Life Sci. 9(8), 347-355.                               
Eronat, E.G.T., Özaydın, O., 2014. Length-weight relationship of cartilaginous fish species from Central Aegean Sea (Izmir Bay and Sığacık Bay). Ege. J. Fish. Aqua. Sci. 31(3), 119-125.    
Giménez, J., Manjabacas, A., Tuset, V.M., Lombarte, A., 2016. Relationships between otolith and fish size from Mediterranean and north‐eastern Atlantic species to be used in predator–prey studies. J. Fish. Biol. 89(4), 2195-2202.
Groeneveld, R.A., Bosello, F., Butenschön, M., Elliott, M., Peck, M.A., Pinnegar, J.K. 2018. Defining scenarios of future vectors of change in marine life and associated economic sectors. Estuar. Coast. Shelf. Sci, 201, 164-171.
Isbert, W., Montero, F.E., Pérez‐del‐Olmo, A., López‐Sanz, À., Reñones, O., Orejas, C., 2018. Parasite communities of the white seabream Diplodus sargus sargus in the marine protected area of Medes Islands, north‐west Mediterranean Sea. J. Fish. Biol. 93(4), 586-596.
Marramà, G., Carnevale, G., Engelbrecht, A., Claeson, K.M., Zorzin, R., Fornasiero, M., Kriwet, J., 2018. A synoptic review of the Eocene (Ypresian) cartilaginous fishes (Chondrichthyes: Holocephali, Elasmobranchii) of the Bolca Konservat-Lagerstätte, Italy. PalZ. 92(2), 283-313.
CrossRef    Google Scholar    full-text PDF    Mendeley    PubMed  
Pike, A., MacKinnon, D., Cumbers, A., Dawley, S., McMaster, R., 2016. Doing evolution in economic geography. Econ. Geogr. 92(2), 123-144.
Reed, J.R., Kerwath, S.E., Attwood, C.G., 2017. Analysis of bycatch in the South African midwater trawl fishery for horse mackerel Trachurus capensis based on observer data. Afr. J. Mar. Sci. 39(3), 279-291.
Veiga, P., Machado, D., Almeida, C., Bentes, L., Monteiro, P., Oliveira, F., Ruano, M., Erzini, K., Gonçalves, J.M.S., 2009. Weight-length relationships for 54 species of the Arade estuary, southern Portugal. J. Appl. Ichthyol. 25(4), 493-496.
Zogaris, S., Tachos, V., Economou, A.N., Chatzinikolaou, Y., Koutsikos, N., Schmutz, S., 2018. A model-based fish bioassessment index for Eastern Mediterranean rivers: Application in a biogeographically diverse area. Sci. Total. Environ. 622, 676-689.