Growth of the burrowing crayfish Parastacus nicoleti (Philippi, 1882) (Crustacea, Decapoda, Parastacidae)

ABSTRACT: We examined the individual growth of the burrowing crayfish Parastacus nicoleti (Philippi, 1882) based on a sample of 1,425 specimens. Individuals were collected monthly from November 1981 to December 1982, in the marshy wetlands of the “Pangal” homestead in Reumen, southern Chile. The Cephalothorax Length (CL) and Body Weight (BW) were recorded for all specimens. The asymptotic length parameters (L ∞) and the growth coefficient (k) were established using the Gulland and Holt method (1959). The t 0 parameter was obtained through the inverse von Bertalanffy equation and the length-weight relationship was determined according to the equation proposed by Ricker (1975). The asymptotic size and weight were 45.754 mm and 18.50 g, respectively. The growth constant was 0.703/year. Estimated longevity was 4.32 years. We concluded that P. nicoleti is a relatively small species with poor growth indicators for size and weight and, consequently, is not an attractive species for commercial aquaculture purposes.

摘要：本研究基于1425份标本样本，探究了穴居螯虾尼科莱副螯虾（Parastacus nicoleti，Philippi, 1882）的个体生长特性。研究样本于1981年11月至1982年12月期间，每月采集自智利南部鲁门地区"潘加尔"庄园的沼泽湿地。所有标本均记录了头胸甲长（Cephalothorax Length, CL）与体质量（Body Weight, BW）。采用古拉德与霍尔特法（Gulland and Holt method, 1959）估算得到渐近体长参数（L∞）与生长系数（k）；t₀参数通过逆向冯·贝塔朗菲方程求得，体长-体质量关系则依据里克（Ricker, 1975）提出的公式确定。本研究测得该物种的渐近体长与体质量分别为45.754 mm与18.50 g，生长常数为0.703/年，预估寿命为4.32年。研究结论表明，尼科莱副螯虾为体型相对较小的物种，其体长与体质量的生长指标较差，因此不具备商业水产养殖开发价值。