age and growth of mesopotamian barb, capoeta damascina, were studied in the zayandehrud river, in central iran, from march 2007 to april 2008. among the 689 specimens studied, age groups in males ranged from 1+ to 9+ and that in females ranged from 1+ to 10+. the sex ratio (1m:1.6f) was not significantly different from 1:1 ratio. maximum fork length and weight was 39 cm and 1,115 g for males an...

Likelihood methods for the von Bertalanffy growth curve are examined under the assumption of independent, normally distributed errors. The following are examined: determining the best method of estimation, relationships between methods of estimation, failure of assumptions, constructing confidence regions, and applying likelihood ratio tests. An eXanlple is presented illustrating many of the me...

The Gompertz function was formulated to represent an actuarial curve, yet it often fits growth of organisms, organs and tumors. Despite numerous attempts, no consensus has been forged about the biological foundation of the broad applicability of the model. Here we revisit the Gompertzian notion of the "power to grow" and equate it with growth fraction. Aside from conferring biological interpret...

The Liangshan pig is a traditional Chinese small-sized breed; it has a relatively long feeding period and low meat production ability but superior meat quality. This study utilized three non-linear growth models (Von Bertalanffy, Gompertz, and logistic) to fit the growth curve of Liangshan pigs from an unselected, random-bred pig population and estimate the pigs most suitable slaughter weight. ...

In this research we proposed two mathematical models for Isoptera mound growth derived from the Von Bertalanffy growth curve, one appropriated for Nasutitermes coxipoensis, and a more general formulation. The mean height and the mean diameter of ten small colonies were measured each month for twelve months, from April, 1995 to April, 1996. Through these data, the monthly volumes were calculated...

population dynamic parameters of red mullet, mullus barbatus (n=592) caught by trawlers operating in arzew gulf (algeria) in the western mediterranean were studied. samples were collected between february 2013 and january 2014. females ranged from 10.9-23.2 cm in total length and 12-149.2 g in weight whereas males length was comprised between 12.6 and 19.7 cm and weight between 21.3 and 99.9 g....

The method of estimating age frequency from length frequency via the von Bertalanffy growth equation is deterministic and yields biased results. Most of the biascan be removed by incorporating a stochastic element in the von Bertalanffy relationship. The stochastic element is based on estimated probabilities of lengths by intervals at age. the probabilities being estimated from variances in len...

Abstract The present investigation aimed to estimate the individual growth and mortality of an invasive species found in estuarine region Patos Lagoon (Southern Brazil). For 20 months crabs were sampled, laboratory specimens Rhithropanopeus harrisii (Gould, 1841) measured (carapace width, CW, weight). Carapace width data was utilized for a modal progression analysis curve (von Bertalanffy model...