{'fraction_non_alphanumeric': 0.04739336492890995, 'fraction_numerical': 0.04874746106973595, 'mean_word_length': 5.370689655172414, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
ASSESSMENT ON BRANCHIOSTOMA BELCHERI STOCK HEALTH IN XIAMEN NATIONAL RARE MARINE SPECIES NATURE RESERVE

In this paper,the stock health of Branchiostoma belcheri in four seasons from 2009 to 2010 in Xiamen National Rare Marine Species Nature Reserve were assessed based on stock distribution,quantity,stock age structure,biological and ecological characteristics of B.belcheri captured by a benthic borrow device.The results showed as follows:(1) B.belcheri is not found in Eyuyu sea waters,while are found in Huangcuo—Qianpu,Xiaodeng—Jiaoyu and Oucuo sea waters,but the densities and their distribution areas are small.(2) The relationship of body mass and body length are:W=6.6895×10 4 L 3.1818 ;and body length and body mass growth are respectively for:L t=65.63[1 e 0.68(t+0.32) ],W t=404.62[1 e 0.68(t+0.32) ] 3.1818.Edge body length group in summer and winter are 25—35mm and 35—45mm respectively,and edge weight group of 25—50mg and 50—100mg.Minor fish are dominant in autumn,while adult fish are dominant in winter.(3) The ELEFANⅠmethod was used to evaluate the Von Bertalanffy growth parameters K,limited length L∞,total mortality coefficient Z,natural mortality coefficient M and exploited rate E.The value of K and M are both high,and the exploited rate are also high (0.69).This suggests that the status of B.belcheri stock is unhealthy,and protection of fish resources must be improved to achieve the sustainability,particularly to their habitat and water quality.