Length-weight relationship and relative condition of Heterobranchus longifilis (Valenciennes) from Idodo River, Nigeria

Length-weight relationship parameters of Heterobranchus longifilis males, females and combined sexes are given. The samples were collected from Idodo River, with size ranging from 123 mm total length, L, to 936 mm L. The values obtained for the mean L by sex show that males were significantly (p<0.05) larger than females. The results show that the slope (b) is significantly (p<0.05) below 3.0 for the male, female and pooled sample. The species exhibit a negative allometric growth pattern. The relative condition of fish shows seasonal variation, with females generally being in better condition than the males.

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 marine fishes from the central Brazilian coast

Parameters of the length-weight relationship are presented for 85 fish species from the marine and estuarine regions of the central Brazilian coast (latitude 13° to 23° S). Three different methods were used. A non-linear iterative process using the quasi-Newton algorithm yielded a better fit for all data sets analyzed. The length-weight allometry coefficient b estimated from standard length data tended to be lower than from total length data. The difference between these estimates was significant for some species.

Length-weight relationship of fishes from a seagrass meadow in Negros Oriental, Philippines

The parameters a and b of the length-weight relationship of the form W=aL super(b) were estimated for 13 fish species sampled in a seagrass meadow in Negros Oriental, Philippines. Also, to facilitate conversions, the relationship between total length and standard length for the 13 species is given.

Length-girth relationships of Barbodes gonionotus and Hampala macrolepidota in the Jatiluhur reservoir, Indonesia

The length-girth relationships of Javanese carp (Barbodes gonionotus) and hampal carp (Hampala macrolepidota) in the Jatilujur Reservoir, Indonesia were examined. The equations derived from estimating the maximum girth of Javanese carp are G sub(m) = -1.19 + 0.80L, and for the hampal carp, G super(m) = -0.47 + 0.62L. Models relating head girth to total length are also given. The relationship between G sub(m) (maximum girth) of fish caught and gillnet mesh size is also briefly discussed.

Length-weight relationship of Gulf of Thailand fishes

The length-weight relationship of 26 fish species belonging to 17 families obtained from the Gulf of Thailand was examined. As seven species were obtained from different survey periods and three were from two different locations, seasonal and geographic variations of the equation between body weight W and total length L, W = aL super(b), were examined. The b values of the 27 species were tested for their significant differences from the value of 3; this confirmed that a few species showed significant differences of b value from 3. It is suggested that the 'cube law (b = 3)' can be applied to the length-weight relationship of most fishes in the Gulf of Thailand, with a few exceptions. This was confirmed by the analysis of b values from 72 additional species from the South China Sea area.

The food habits of hatchery-produced pond-cultured shad (Alosa sapidissima) reared to a length of two inches

The present study was aimed at determining the food habits of hatchery-produced, pond-cultured shad (Alosa sapidissima) reared to a total length of approximately two inches. More specifically, the objectives were to determine: (1) That point in life at which young shad start to consume food; (2) What type or types of food the young shad consume at the onset of feeding; (3) Food changes, if any, which occur with age and growth in size up to the arbitrarily designated total length of two inches. The plan was that the shad larvae be introduced into an outdoor rearing pond previously fertilized, and that the larvae be dependent upon the plankton for food as they would be under natural conditions.

Differences in diet of Atlantic bluefin tuna (Thunnus thynnus) at five seasonal feeding grounds on the New England continental shelf

The stomachs of 819 Atlantic bluefin tuna (Thunnus thynnus) sampled from 1988 to 1992 were analyzed to compare dietary differences among five feeding grounds on the New England continental shelf (Jeffreys Ledge, Stellwagen Bank, Cape Cod Bay, Great South Channel, and South of Martha’s Vineyard) where a majority of the U.S. Atlantic commercial catch occurs. Spatial variation in prey was expected to be a primary influence on bluefin tuna distribution during seasonal feeding migrations. Sand lance (Ammodytes spp.), Atlantic herring (Clupea harengus), Atlantic mackerel (Scomber scombrus), squid (Cephalopoda), and bluefish (Pomatomus saltatrix) were the top prey in terms of frequency of occurrence and percent prey weight for all areas combined. Prey composition was uncorrelated between study areas, with the exception of a significant association between Stellwagen Bank and Great South Channel, where sand lance and Atlantic herring occurred most frequently. Mean stomach-contents biomass varied significantly for all study areas, except for Great South Channel and Cape Cod Bay. Jeffreys Ledge had the highest mean stomach-contents biomass (2.0 kg) among the four Gulf of Maine areas and Cape Cod Bay had the lowest (0.4 kg). Diet at four of the five areas was dominated by one or two small pelagic prey and several other pelagic prey made minor contributions. In contrast, half of the prey species found in the Cape Cod Bay diet were demersal species, including the frequent occurrence of the sessile fig sponge (Suberites ficus). Prey size selection was consistent over a wide range of bluefin length. Age 2–4 sand lance and Atlantic herring and age 0–1 squid and Atlantic mackerel were common prey for all sizes of bluefin tuna. This is the first study to compare diet composition of western Atlantic bluefin tuna among discrete feeding grounds during their seasonal migration to the New England continental shelf and to evaluate predator-prey size relationships. Previous studies have not found a common occurrence of demersal species or a pre-dominance of Atlantic herring in the diet of bluefin tuna.

Length-weight relationship Megalaspis cordyla (Linnaeus, 1758) along north west coast of India

Total length and total weight relationship of Megalaspis cordyla (Linnaeus, 1758) a carangid fish, along north west coast of India has been worked out. The fish is an ideal one, growing by weight a cube of its length, isometrically, retaining its specific body shape throughout its life. The relationship is w = 0.00906279 L super(2.9024152) total weight of fish in g and "L" represents total length in cm.

Length-weight relationship and relative condition factor in Macrobrachium (Hellex)

The length-weight relationship was calculated for the freshwater prawn Macrobrachium idae. About 150 specimens of M. idae (males 50, females 50 and 50 juveniles) were utilised for this study. The length-weight relationship was assessed separately for males, females and indeterminants. The regression equation for males, females and indeterminants showed significant differences whereas it was insignificant for males and females. The variations in length-weight relation between sexes and indeterminants were compared and discussed. The relationship between total length with carapace length and total length with rostral length were also determined.

Length-weight relationship and condition factor of black carp (Mylopharyngodon spiceus Richardson) in Bangladesh

The length-weight relationship and condition factor of Mylopharyngodon spiceus were determined. The result of the study showed the dependence of weight (W) on the total length (L) in the following form: W= 0.006L(super 3.156) or in the logarithmic form Log W=- 2.1851 + 3.156 Log L. Standard errors of length and weight were 0.674 cm and 3.214 g respectively. The co-efficient correlation "r" was found to be 0.972 which indicated that the relationship between length and body weight of the fish was highly significant. The t-test also indicated that the correlation between length and weight was significant. The range and mean value of condition factor (K) were 0.865 to 1.041 and 0.958 respectively.

Preliminary observations on the morphometric characteristics, length weight relationship, food and fedding habits and fecundity of Saurida tumbil (Bloch) off Bombay coast

Fifteen morphometric and four meristic characters of Saurida tumbil were studied and their relationships with total length and head length were established. The length weight relationship worked out to be W= -5.6055 L(super)3.291. The fish is a carnivore, feeding mainly on small fishes, molluscs and crustaceans. Larger fishes are selective feeders on fish. It is a long protracted spawner. Fecundity varied from 6008 to 17384 eggs in specimens of size group 212-420 mm. Fecundity-total length, fecundity-total weight of fish and fecundity - total weight of ovary relationships were worked out to be F=0.9414 L(super)1.6626, F=180.7069 W(super)0.7531 and F=3153.0375 W(super)0.8278 respectively.

Length-weight relationship of a hill-stream fish, Glyptothorax telchitta (Ham.) from Saptakoshi River of Nepal

The length-weight relationship of a hill-stream fish, Glyptothorax telchitta from Saptakoshi River of Nepal was analysed using the formula W=aLᵇ. The exponential values computed for total length and standard length in relation to body weight were 2.991 and 2.888 respectively.

Morphometrics, length-weight relationship and condition of Rastrineobola argentea (Pellegrin 1904) in the Winam Gulf of Lake Victoria (Kenya)

Correlation between total length (TL), fork length (FL) and standard length (SL) of Raslrineobola argentea (pellegrin 1904) in the Winam Gulf of Lake Victoria indicate that FL = 0.92 TL - 0.74 and SL = 0.90 TL - 1.74. Length-weight relationship of log-transformed data shows that the slopes of the regression lines were 3.06 to 3.22 for juveniles, 2.70 to 3.05 for males and 3.24 to 3.71 for females. The slopes were significantly different between groups at at a =0.05. The Fulton's condition factor (K) was highest in December (1.019-1.073) and March/April (1.015-1.030) but lowest in June (1:00-1.025) for all stations. Significant differences between groups demands for the use of different growth models for juveniles, males and females especially for the von Bertalanffy growth equation which uses length-weight relationship. Observed cyclic viations in condition factor suggests two peak breeding seasons for this species in the Winam Gulf. The practical lmplications of these results in stock assessment using length-based fish stock assessment methods is briefly discussed.

GENETIC MAPPING OF THE LAMINARIA JAPONICA (LAMINARALES, PHAEOPHYTA) USING AMPLIFIED FRAGMENT LENGTH POLYMORPHISM MARKERS

To establish a molecular-marker-assisted system of breeding and genetic study for Laminaria japonica Aresch., amplified fragment length polymorphism (AFLP) was used to construct a genetic linkage map of L. japonica featuring 230 progeny of F-2 cross population. Eighteen primer combinations produced 370 polymorphic loci and 215 polymorphic loci segregated in a 3:1 Mendelian segregation ratio (P <= 0.05). Of the 215 segregated loci, 142 were ordered into 27 linkage groups. The length of the linkage groups ranged from 6.7 to 90.3 centimorgans (cM) with an average length of 49.6 cM, and the total length was 1,085.8 cM, which covered 68.4% of the estimated 1,586.9 cM genome. The number of mapped markers on each linkage group ranged from 2 to 12, averaging 5.3 markers per group. The average density of the markers was 1 per 9.4 cM. Based on the marker density and the resolution of the map, the constructed linkage map can satisfy the need for quantitative trait locus (QTL) location and molecular-marker-assisted breeding for Laminaria.