Morphology and fisheries biology of the Taiwan saddled carpetshark (Cirrhoscyllium formosanum)

• Main Authors: Jing-Chun Huang, 黃敬淳
• Other Authors: Hsuan-ching Ho
• Format: Others
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/47309629389269075820

碩士 === 國立東華大學 === 海洋生物研究所 === 105 === The Taiwan saddled carpetshark, Cirrhoscyllium formosanum, is a small benthic shark that only found in the southwestern Taiwan. With the overfishing pressure caused by the bottom trawlers, its population may have decreased largely. Because of the lacks of basic biological data, its conservation can be ignored easily. This study investigated the morphology, reproduction, age and growth of this shark. The results include: 1. Females are larger in size than males (L_max=430 mm in females and 383 mm in males); 2. Sexual dimorphism and allometry growth are present in the population. The proportion of fins show a positive growing trend and the males have a greater distance between the pelvic fin and the anal fin; 3. The GSI, SGSI and diameter of oocytes peaked of mature females occurred in March and fell to the lowest value in June that suggested the breeding season is the summer. Reproductive potential is 4.69 ± 1.42 oocytes; 4. there are 0-3 rings can be determinated on vertebrae and the ring may form in May and June. The von Bertalanffy growth function (VBGE) is L_∞= 453.53 mm, t_0= -0.26 and K= 0.520 in females and L_∞= 389.37 mm, t_0= -0.21 and K= 0.666 in males. Detailed biological information is provided which can be used as basic data for conservation assessments of the species.