Length-weight and tail length-total length relationship in Panulirus homarus Linnaeus on the south-west coast of India

Length-weight relationships of Panulirus homarus caught from the Kanniyakumari coast was found to be W=0.000566 L super(2-50). The relationship between tail length and total length was also investigated and compared with that of Panulirus polyphagus. Same relationship did not hold good for the two sexes as in the case of P. polyphagus. For a given tail length, the head length, the total length and the weight appear to be relatively larger for females of small sizes of P. homarus.

Reproductive characteristics and the weight-length relationship in Anableps anableps (Linnaeus, 1758) (Cyprinodontiformes: Anablepidae) from the Amazon Estuary

O presente estudo analisou a relação peso-comprimento e uma série de aspectos da biologia reprodutiva de Anableps anableps da foz do rio Maracanã, no estado brasileiro do Pará. Os espécimes foram coletados por meio de duas redes de emalhar de 30 m de comprimento, com malhas de 15 e 20 mm, e com um puçá com um metro de diâmetro, com malha de 10 mm. Foram capturados 865 espécimes, os quais foram analisados para estabelecer a razão sexual, que foi de 2,12 fêmeas por macho (χ² = 13,07; p<0,05). As fêmeas apresentaram crescimento alométrico positivo, enquanto que os machos foram alométricos negativos. Nas análises adicionais, as gônadas de 371 fêmeas foram observadas ao microscópio. O desenvolvimento gonadal foi classificado em três estádios: imaturo (5,0%), em maturação (12,0%) e maturo (83,0%). O desenvolvimento embrionário foi classificado em cinco fases, de acordo com o tamanho do embrião e do saco vitelino. A fecundidade média foi de 12 ovos / embriões por fêmea (variando de 1-37 ovos / embriões). Uma relação significativa foi verificada entre o comprimento padrão das fêmeas, o peso de seus ovários (R² = 0,257, p < 0,001), e o número de embriões (R² = 0,573, p < 0,001). O tamanho médio da primeira maturação sexual (L₅₀) para as fêmeas foi estimado em 11,7 cm. A espécie se reproduz durante todo o ano.

Length-weight relationships of demersal fishes from the upper continental slope off Colombia

Parameters of the length–weight relationship of the form W=aLb are presented for 45 demersal fish species caught on the upper continental slope of the Caribbean Sea off Colombia. The b values varied between 2.13 and 4.97, with the mean b = 3.042 (95% CI, 2.887- 3.196).

Length-weight studies of Epinephelus chlorostigma and E. areolatus from Arabian Gulf

Regression coefficient value (b) of the length-weight relation of Epinephelus chlorostigma was registered as 2.6383, which is significantly (p<0.01) less than the hypothetical value (3). This coefficient of E. areolatus was registered as 2.9500, a value close to 3. The correlation coefficients (r) were registered as 0.9725 and 0.9837 for E. chlorostigma and E. areolatus, respectively, which show a good relationship between the two parameters.

Length-weight relationships of 29 fish species from the Tucurui Reservoir (Tocantins/Araguaia Basin, Brazil)

The length-weight relationships (LWRs) are described for 29 fish species in the region of the Tucurui Reservoir, located in the Tocantins/Araguaia Basin, northern Brazil. Fishes in fourteen sites were sampled seasonally for 10 years, from 2001 to 2010. Significant differences between sexes were found for two species, while 27 species had similar LWRs for males and females. The relationship of standard length and total length is presented for all species as well as the minimum and average size of reproductive females and seasonality of occurrence. No information on LWRs of these 29 species was heretofore available in FishBase.

Limacina helicina size weight relationship in Kongsfjorden Svalbard, May 2009

Thecosome pteropods (pelagic mollusks) can play a key role in the food web of various marine ecosystems. They are a food source for zooplankton or higher predators such as fishes, whales and birds that is particularly important in high latitude areas. Since they harbor a highly soluble aragonitic shell, they could be very sensitive to ocean acidification driven by the increase of anthropogenic CO2 emissions. The effect of changes in the seawater chemistry was investigated on Limacina helicina, a key species of Arctic pelagic ecosystems. Individuals were kept in the laboratory under controlled pCO2 levels of 280, 380, 550, 760 and 1020 µatm and at control (0°C) and elevated (4°C) temperatures. The respiration rate was unaffected by pCO2 at control temperature, but significantly increased as a function of the pCO2 level at elevated temperature. pCO2 had no effect on the gut clearance rate at either temperature. Precipitation of CaCO3, measured as the incorporation of 45Ca, significantly declined as a function of pCO2 at both temperatures. The decrease in calcium carbonate precipitation was highly correlated to the aragonite saturation state. Even though this study demonstrates that pteropods are able to precipitate calcium carbonate at low aragonite saturation state, the results support the current concern for the future of Arctic pteropods, as the production of their shell appears to be very sensitive to decreased pH. A decline of pteropod populations would likely cause dramatic changes to various pelagic ecosystems.

Seasonal foods, gonadal maturation, and length-weight relationships for nine fishes commonly captured by shrimp trawl on the Northwest Gulf of Mexico Continental Shelf

Recent emphasis on ecosystem approaches to fisheries management renews interest in, and the need for, trophic information about fish communities. A program was started in 1980 at the National Marine Fisheries Service Galveston Laboratory to develop a trophic database for continental shelf fishes. Collections were made during 1982-1983 that were processed but never published, yet the data remain valid today for historical purposes and for delimiting food web components within ecosystem assessments. I examined spring, summer, and fall foods in offshore populations of nine common species of trawl-susceptible fishes, with particular reference to predation on commercial penaeid shrimps (Farfantepenaeus and Litopenaeus). Diets were evaluated with the Index of Relative Importance (IRI) which combines the occurrence, number, and weight of each food item. Bank sea bass (Centropristis ocyurus) and bighead searobin (Prionotus tribulus) primarily consumed crabs, more so by larger than smaller fish. Inshore lizardfish (Synodus foetens) was almost entirely piscivorous. Ocellated flounder (Ancylopsetta ommata) consumed fishes, crabs, and stomatopods. Dwarf sand perch (Diplectrum bivittatum), blackwing searobin (Prionotus rubio), rock sea bass (Centropristis philadelphica), southern kingfish (Menticirrhus americanus), and red snapper (Lutjanus campechanus) fed mainly on shrimps. Most fish diets varied with respect to size (age), time of day, area sampled, depth, or season. Rimapenaeus and Sicyonia were the most frequently identified shrimp genera - only five Farfantepenaeus and no Litopenaeus were identified in almost 4,300 fish stomachs. I also examined gonadal development and documented fish length-weight relationships. Ripe gonads were most frequently found during summer in dwarf sand perch, during fall in ocellated flounder and bighead searobin, and during spring for other species, except no ripe red snapper or bank sea bass were collected. Rock sea bass was found to be a protogynous hermaphrodite, while dwarf sand perch is a synchronous hermaphrodite. Only ocellated flounder and southern kingfish exhibited sex-related differences in length-weight relationships. (PDF contains 40 pages.)

Length-weight relationships of the anchoveta, Cetengraulis mysticetus, in the Gulf of Panama

ENGLISH: Knowledge of the length-frequency distribution and the length-weight relationships of the anchoveta is essential for converting the catch statistics of that species from pounds to numbers of fish. Such conversions are necessary for various types of investigations, especially those involving estimation of the population size and mortality rates. The analysis of the results of a recent tagging program conducted with anchovetas in the Gulf of Panama (Bayliff, 1965) requires that such conversions be made. Length-frequency data for the anchoveta have already been collected and published (Howard and Landa, 1958; Bayliff, 1964). The present report deals with length-weight data from fish collected in various .areas of the Gulf of Panama in all months of the year and in several different years. Opportunity is thus afforded to compare the length-weight relationships of fish of different year classes in different areas, months, and years. SPANISH: El conocimiento de la distribución de la frecuencia de longitud y de las relaciones entre la longitud y el peso de la anchoveta es esencial en las estadísticas de captura de esta especie para la conversión de peso en libras a número de peces. Estas conversiones son necesarias para varios tipos de investigación, especialmente las que se refieren a la estimación del tamaño de la población y de las tasas de mortalidad. Estas conversiones se requieren para analizar los resultados de un programa reciente de marcación de anchovetas en el Golfo de Panamá (Bayliff, 1965). Los datos de la frecuencia de longitud de la anchoveta ya han sido recolectados y publicados (Howard y Landa, 1958; Bayliff, 1964). El presente informe trata de los datos de longitud y peso de los peces recolectados en varias áreas del Golfo de Panamá durante todos los meses del año y durante varios años. Esto ofrece la oportunidad de comparar las relaciones entre la longitud y el peso de peces pertenecientes a varias clases anuales en áreas, meses y años diferentes.

Length-weight relationships of major carps in Kaptai Lake, Bangladesh

Length-weight relationships and condition factors are presented for Indian major carp Catla catla, Labeo rohita, L. calbasu and Cirrhinus mrigala (Cyprinidae) in a reservoir of Bangladesh (Kaptai Lake).

Length-weight relationships of fishes from tributaries of the Volta River, Ghana Part 1: Analysis of pooled data sets

The parameters a and b of length-weight relationships of the form W = a L super(b) were estimated for 45 fish species sampled in the Oti, Pru and Black Volta rivers, Ghana. Also, the slope and intercepts of regressional enabling standard to total length conversions were estimated for each of these same species. The estimates of b, which ranged from 2.35 to 3.27 have a mean of 2.98, with a s.e. of 0.036. These results are complemented with a brief discussion of the need for data summaries such as presented in this article.

Length-weight relationships of Cuban marine fishes

A total of 140 sets of parameters (a and b) of the length-weight relationships (LWR) of the form W=aL super(b) are presented for fishes caught in Cuban waters. These parameters cover 94 species of fish belonging to 43 families. Most of the parameters were compiled from 107 sets of published and unpublished studies. Twenty-five sets of parameters were from personal communications through colleagues in Cuba, while the remaining eight sets were estimated by the authors from unpublished data.

Length-weight relationships of coral reef fishes from the Alacran Reef, Yucatan, Mexico

Length-weight relationships were computed for 42 species of coral reef fishes from 14 families from the Alacran Reef (Yucatan, Mexico). A total of 1 892 individuals was used for this purpose. The fish species were caught by different fishing techniques such as fishhooks, harpoons, gill and trawl nets. The sampling period was from March 1998 to January 2000.

Length weight relationships of Nigerian freshwater fishes

Length-weight relationships of 73 fish populations, covering 20 families, 28 genera and 40 species inhabiting freshwater ecosystems in Nigeria, were estimated (73 cases) or assembled from the literature (20 cases), and tested for difference between ecosystem types, There were no significant differences in the exponent of these relationships between lotic and lentic systems.

Length-weight relationships of Nigerian coastal water fishes

Length-weight relationships (LWR) of 76 fish populations, distributed among 11 families, 18 genera and 22 species, inhabiting coastal (marine/brackish water ) ecosystems in Nigeria were estimated (39 cases) or assembled from the literature (37 cases). The mean exponent (b = 2.912) is significantly less than 3. While the frequency distribution of a was positively skewed, that of b was approximately normal. The mean a and b data are also presented by fish genera and families.