Age and growth for the scalloped hammerhead shark, sphyrna lewini (griffith and smith, 1834) along the central pacific coast of mexico
Article Sidebar
Main Article Content
Abstract
The age and growth of the scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834) were estimated from rings on the vertebral centrum in 101 individuals (51 females and 50 males) from 260 organisms obtained from commercial fisheries off the coast of Michoacán, Mexico (18º10'N, 103º10'W). Results show that immediately after birth, a first ring is formed. Later we observed that two rings are formed each year, one between June and July and the other between November and December. The parameters of the von Bertalanffy growth function were, for females, L∞ = 353.3 cm, K = 0.156 cm yr–1, t0 = –0.633 years, b = 2.8 and W∞ = 269.92 kg; and, for males, L∞ = 336.4 cm, K = 0.131 cm yr–1, t0 = –1.09 years, b = 2.87 and W∞ = 187 kg. According to these results, a female 335.6- cm-long would be 18.6 years old and a male of 244.3 cm would be 8.8 years old.
Downloads
Article Details
This is an open access article distributed under a Creative Commons Attribution 4.0 License, which allows you to share and adapt the work, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Figures, tables and other elements in the article are included in the article’s CC BY 4.0 license, unless otherwise indicated. The journal title is protected by copyrights and not subject to this license. Full license deed can be viewed here.