Age, Growth and Sex Ratio of the Azorean Rock-Pool Blenny, Parablennius Sanguinolentus Parvicornis

The age and population structure of Parablennius sanguinolentus parvicornis (Valenciennes) (Pisces: Blenniidae) from the Azores have been studied. Total length and weight relationships are given for each sex. Age study was based on otoliths readings. The von Bertalanffy growth function was applied to describe the growth in total length with age. At the end of the first year mean (±SD) total length was significantly different in males (7.1 ±1.5 cm) and females (6.1 ±1.2 cm). One-year-old males participate in reproduction as satellites, whereas females do not. The implications of this in early growth rate of the males is discussed. During the two most important months of the reproductive season (i.e. June and July), the sex ratio was significantly biased towards males, particularly in the larger size classes.

Download Full-text

Natural Growth and Mortality of the Golden Grey Mullet Liza Aurata (Risso, 1810) In the Lagoon of Klisova-Messolonghi (W. Greece)

Academic Journal of Life Sciences ◽

10.32861/ajls.54.23.31 ◽

2019 ◽

pp. 23-31 ◽

Cited By ~ 1

Author(s):

George N. Hotos

Keyword(s):

Growth Parameters ◽

Age Determination ◽

Growth Curves ◽

Growth Function ◽

First Year ◽

Annual Growth Rate ◽

Von Bertalanffy ◽

Liza Aurata ◽

Total Length ◽

Von Bertalanffy Growth Function

Growth and mortality of L. aurata (Risso,1810) were estimated in the lagoon of Klisova-Messolonghi (W. Greece), based on age estimation from scale readings of a total of 1048 individuals, ranging between 10 and 59 cm in total length (TL). Age determination revealed nine age classes (0+ to 8+). Maximum age was found to be 8 years for females and 6 years for males respectively. The growth pattern of L. aurata exhibited allometry (b=3.26). The species seems to achieve 34% of its growth during the first year; thereafter the annual growth rate drops. Both sexes presented similar von Bertalanffy growth curves. The von Bertalanffy growth function for the estimated total length-at-age was found Lt = 70.78 [1 - e -0.129(t+1.345)] for the combined sexes. Otolith weight, length and width were tested and they were found to be very good predictors for age. Between the present L. aurata growth parameters and those of other Mediterranean, Caspian and Atlantic Sea for the same species, there were found significant differences in its growth parameters. The total (Z) and natural (M) mortality rate was found to be 0.54 years-1 and 0.33 years-1 respectively. The estimated exploitation rate was found to be E=0.395 which suggests that the existing fishing pressure on L. aurata is rather moderate in the investigated region.

Download Full-text

Age, growth and reproduction of the Morocco dentex Dentex maroccanus of the eastern coast of Algeria

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315414001945 ◽

2014 ◽

Vol 95 (6) ◽

pp. 1261-1270

Author(s):

Rima Mohdeb ◽

M. Hichem Kara

Keyword(s):

Gonadosomatic Index ◽

Growth Function ◽

Reproductive Season ◽

Eastern Coast ◽

Von Bertalanffy ◽

Total Length ◽

Reproduction Study ◽

Dentex Dentex ◽

Size At Age ◽

Growth And Reproduction

A total of 1725 specimens of Dentex maroccanus caught in the eastern coast of Algeria from June 2011 to May 2012 were examined for an age and reproduction study. Total length (TL) ranged from 10.4 cm (16.05 g) to 26.8 cm (300.80 g). The maximum estimated age was 7 years for females and 8 years for males. The growth function of Von Bertalanffy fitted to back-calculated size at age data was: TL = 36.64[1 − e−0.2(t−0.5)] and TL = 37.26[1 − e−0.2(t−0.5)] for females and males respectively. Total length – eviscerated weight (We) relationship was estimated as We = 0.012 TL3.046 for females and We = 0.011 TL3.067 for males, being allometrically positive for both sexes. Sex-ratio was 1:0.9 in favour of females. A five-stage maturity scale based on macroscopic characteristics was identified and used to classify the gonads. The reproductive season, evaluated from a gonadosomatic index, extended from May to September. Fifty per cent maturity of the tested sample was reached at a total length of 14.4 cm TL for females and 15.1 cm TL for males.

Download Full-text

An Antarctic shelf population of the deep-sea, Pacific brachiopod Neorhynchia strebeli

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400071757 ◽

1997 ◽

Vol 77 (2) ◽

pp. 399-407 ◽

Cited By ~ 7

Author(s):

David K.A. Barnes ◽

Lloyd S. Peck

Keyword(s):

Deep Sea ◽

Growth Function ◽

Weddell Sea ◽

Von Bertalanffy ◽

Growth Rings ◽

Von Bertalanffy Growth Function ◽

Annual Periodicity ◽

A Site ◽

The Antarctic ◽

Order Rhynchonellida

Thirty-five specimens of the articulate brachiopod Neorhynchia strebeli were collected from a site at 814 m in the Weddell Sea. This was only the second species of the order Rhynchonellida to be found in Antarctica. Formerly N. strebeli was known solely from abyssal Pacific Ocean localities. A circumantarctic distribution is suggested in addition to the known deep-sea Pacific range. The specimens of this collection showed considerable commissure variation, suggesting that the previously proposed erection of two subspecies on the basis of this character is erroneous, and emphasises the phenotypic plasticity of some articulate brachiopods. The valve lengths and the number of alpha growth rings in the sample showed a normal distribution and a von Bertalanffy growth function was fitted to the data: Lt = 23 (1-exp[-0·228t]). If the alpha growth rings were of annual periodicity, the ages attained by the Antarctic N. strebeli of 11 y would be substantially lower than those reported for other Weddell Sea brachiopods. The epibiotic communities occurring on the valves of N. strebeli were impoverished, which is characteristic of deep water Antarctic brachiopods. The few specimens collected with their substratum were attached to small pebbles, but the typical attachment substrata may be different.

Download Full-text

Age, growth and mortality of Sciaena umbra (Sciaenidae) in the Gulf of Tunis

Scientia Marina ◽

10.3989/scimar.04679.21a ◽

2018 ◽

Vol 82 (1) ◽

pp. 17 ◽

Cited By ~ 3

Author(s):

Inès Chater ◽

Ahlem Romdhani-Dhahri ◽

Jean Louis Dufour ◽

Kélig Mahé ◽

Nadia Chakroun-Marzouk

Keyword(s):

Cross Sections ◽

Growth Function ◽

Growth Increment ◽

Total Weight ◽

Marginal Analysis ◽

Positive Allometry ◽

Total Length ◽

Gulf Of Tunis ◽

Von Bertalanffy Growth Function ◽

Log Linear

The growth and mortality of the brown meagre, Sciaena umbra from the Gulf of Tunis, were investigated using a sample of 276 specimens, ranging from 15.3 to 49.2 cm total length and from 43 to 1565 g total weight. Specimens were collected from artisanal fisheries between October 2008 and September 2011. Otoliths were extracted, thin cross-sections were realized and radii were measured. The log-linear morphometric relationships between total length-total weight and total length-otolith radius were significant (p < 0.05), showed positive allometry (b=3.15) and isometry (b=0.90), respectively. The marginal analysis suggested that only one growth increment was deposited per year. The maximum age of the brown meagre was 22 years for males and 31 years for females. The fit of the von Bertalanffy growth function was significantly different between sexes (p

Download Full-text

Comparing Polynomial and von Bertalanffy Growth Functions for Fitting Tag–Recapture Data

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-169 ◽

1994 ◽

Vol 51 (8) ◽

pp. 1689-1691 ◽

Cited By ~ 2

Author(s):

William S. Hearn ◽

George M. Leigh

Keyword(s):

Growth Function ◽

Growth Increment ◽

Bias Reduction ◽

Release Time ◽

Von Bertalanffy ◽

Growth Functions ◽

Straight Line ◽

Von Bertalanffy Growth Function ◽

Multiple Measurements ◽

The One

The properties of polynomial and von Bertalanffy growth functions are compared for analysing data from tag–recapture experiments in which fish are recaptured once. For the quadratic and von Bertalanffy growth functions, explicit formulae are obtained for the expected growth increment in terms of length-at-release, time-at-liberty, and the function parameters. If the least-squares fitting technique is used the von Bertalanffy function fits tag–recapture data with no more bias (probably less) than any other growth function, including polynomial growth functions. A bias-reduction technique for fitting the von Bertalanffy growth function to tag–recapture data is not applicable to other growth functions. We conclude that, apart from the straight line, the von Bertalanffy growth function is the one with the most desirable mathematical and statistical properties for fitting to tag–recapture data. The matter of the function that best characterises the way a specific fish species grows can be adequately addressed only by analyses of multiple measurements of individual fish.

Download Full-text

A new model accounting for seasonal cessation of growth in fishes

Marine and Freshwater Research ◽

10.1071/mf9921151 ◽

1992 ◽

Vol 43 (5) ◽

pp. 1151 ◽

Cited By ~ 39

Author(s):

S Pauly ◽

M Soriano-Bartz ◽

J Moreau ◽

A Jarre-Teichmann

Keyword(s):

Salmo Salar ◽

Growth Function ◽

Sine Wave ◽

Smooth Transition ◽

Von Bertalanffy ◽

New Model ◽

Von Bertalanffy Growth Function ◽

Zero Growth ◽

Key Features ◽

Summer Growth

A modified version of the von Bertalanffy growth function (VBGF) is proposed in which a sine wave modifies a standard version of the VBGF, enabling a smooth transition between rapid summer growth and a variable period of zero growth (in length) during winter or during the dry season for aestivating fishes. The key features of a nonlinear routine for fitting this new model are also presented, with emphasis on the estimation of the period of zero growth. Application examples, to Salmo salar and Trisopterus esmarkii, are presented.

Download Full-text