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1.
本研究所用标本为7种水生甲虫,均采自伊朗Choghakhor沼泽。通过对水生甲虫的体长和体重的测量,研究其体长-体重关系(LWR)。结果表明: LWR参数b的变动范围在2.315~3.117之间。所有被观察的水生甲虫体长与体重关系明显,相关系数(r2)均高。本研究所得到的这种相互关系可被用于确定甲虫体重,并有助于解决其他的一些生态学问题。本研究所提出的体长-体重关系(LWR)限制于所观察到的标本体长范围。  相似文献   

2.
This study presents length‐weight relationships (LWR) for 19 species captured in the Jacuí Delta in southern Brazil. Most of the species had no previous LWR estimates.  相似文献   

3.
The length‐weight relationships or LWR (W = aLb) of 18 of the 21 fish species caught in 2007–2008 from the Candaba wetland in central Luzon, Philippines are reported. These species belong to 14 families and the LWR of six species are first documented in this paper. Cyprinids comprised the greatest number of species. The high significance of the LWR parameters indicate that fish weight may be predicted from length, at least within the range of the fish lengths recorded. This first reference to the LWR of fishes from the Candaba wetland provides baseline data for the conservation management of fish biota in this threatened ecological resource.  相似文献   

4.
This study provides data on the length‐weight relationships (LWR) for 26 tropical fish species collected in August 2010 (dry season) and May 2011 (wet season), and represents the first LWR references for these species in the small tributary streams flowing into the major rivers of the Pantanal Matogrossense, Brazil.  相似文献   

5.
Length‐weight relationships (LWR) and length‐length relationships (LLR) were analyzed for three species inhabiting tidepools in the Amazon Coastal Zone, two of them non‐native. Tidepools were sampled in five beaches along the Amazon Coastal Zone in 2011, and samplings were carried out using hand nets. The coefficients of allometry and proportionality were within the ranges estimated for fishes. All three species exhibited coefficients of allometry (b) higher than 3 in the LWR.  相似文献   

6.
The present investigation gives the length‐weight relationship (LWR) of Puntius shalynius in Meghalaya, India. The samples for the study were collected from Umiam river. The value of the exponent ‘b’ in the LWR was less than 3, with 0.885 for males and 1.616 in females. This shows that the species exhibit allometric growth pattern. There was no difference in LWR between sexes and seasons.  相似文献   

7.
The present study provides length‐weight (LWR) and total length‐standard length (LLR) relationships for 16 freshwater fish species collected in coastal rivers of the northern Brazilian, state of Amapá in 2015. Fishes were caught in heterogenic environments like ponds, stream and river channel with sieve and trawl. As result, we present novel information of LWR and LLR for 11 and 15 species, respectively. Maximum values (first values or new maximum values) of TL, SL and WT are presented for 14, 12 and 15 species, respectively.  相似文献   

8.
This paper presents length‐weight relationships (LWR) for 22 species from the Pitangui River Basin, Brazil. For six of these species these are the first LWR records; for nine other species these are the first LWRs recorded in FishBase.  相似文献   

9.
A Bayesian hierarchical approach is presented for the estimation of length‐weight relationships (LWR) in fishes. In particular, estimates are provided for the LWR parameters a and b in general as well as by body shape. These priors and existing LWR studies were used to derive species‐specific LWR parameters. In the case of data‐poor species, the analysis includes LWR studies of closely related species with the same body shape. This approach yielded LWR parameter estimates with measures of uncertainty for practically all known 32 000 species of fishes. Provided is a large LWR data set extracted from www.fishbase.org , the source code of the respective analyses, and ready‐to‐use tools for practitioners. This is presented as an example of a self‐learning online database where the addition of new studies improves the species‐specific parameter estimates, and where these parameter estimates inform the analysis of new data.  相似文献   

10.
The present study provides the estimates of length‐weight relationships (LWRs) and length‐length relationships (LLRs) of two gobiid fishes Eleotris fusca and Odontamblyopus rubicundus from the Payra River, southern Bangladesh. Fish samples were collected from the set bagnet (mesh size <2 mm) fishers of the Payra River in July 2016. Allometric coefficient (b) values were 2.95 for E. fusca and 2.76 for O. rubicundus. Additionally, the LLRs were highly significant with r2 ≥ .955. While the estimate of the LWR for O. rubicundus includes a substantial larger sample size and thus provides a more reliable LWR than the one published so far, the LWR for E. fusca must be considered as tentative because the sample includes only juveniles for a fish that reaches a maximum standard length more than three times as much. Additional studies are needed to further improve our LWR knowledge base for these fish species.  相似文献   

11.
The present study provides the length‐weight relationship (LWR) for 21 fish species from eight rivers from Rio Doce River basin, Minas Gerais States, Brazil. Fishes were collected between August 1991 and September 2017, with gillnets, hand nets, cast nets and trawl nets. Standard length and total weight were measured for the LWR, which allometric coefficients b varied from 2.621 to 3.146.  相似文献   

12.
The present study established the length‐weight relationships (LWR) for seven fish species from Jequitinhonha River basin, a Brazilian coastal drainage, collected with gillnets (3 to 16 cm) between 2011 and 2016. For the LWR, standard length and total weight were used. The allometric coefficient b varied from 2.66 to 3.26. These results provide biological data for a region of extreme biogeographical importance that is suffering serious environmental disturbances.  相似文献   

13.
This study provides length–weight relationship (LWR) information for two fish species (family Cyprinidae), Crossocheilus latius (Hamilton, 1822) and Garra gotyla gotyla (Gray, 1830), from a tributary of the Ganga River Basin, India. Both species had no previous LWR estimates as per Fishbase 2014.  相似文献   

14.
Length‐weight (LWR) and length‐length (LLR) relationships were estimated for 20 species and lengths at first maturity (L50) for six species of freshwater fishes caught in the Salto Santiago Reservoir, Iguaçu River Basin, Brazil. In nine species significant differences were found in the LWR between sexes. Average b‐value for species with no differences between sexes in LWR was 3.12 (SE = ±0.05). Average b‐value in LLR was 0.823. First references on LWRs and L50 are presented for 13 and four fish species, respectively, as well as the new maximum total lengths for eight species.  相似文献   

15.
Length–weight relationships (LWR) of fishes are necessary for various purposes such as stock/ecological assessment, monitoring and management (Froese, 2006). In this study we report length–weight relationships for five species of stingrays found in the Persian Gulf, Iran. Only one LWR was previously reported in the scientific literature for Rhinoptera javanica (Raje, 2000).  相似文献   

16.
This paper presents length–weight relationships (LWR) for 11 freshwater fish species from the Sapucaí‐Mirim River, a tributary of the Grande River basin, São Paulo, Brazil. The specimens were captured in quarterly samplings between March 2011 and December 2014, using gillnets of mesh size: 1.5–9.0 cm between knots. The present study adds new information for the maximum length of seven species, and presents new LWR records for four species.  相似文献   

17.
Long-term environmental monitoring studies includes morphometric data (length and weight) of aggregating fish species around this artificial structure and adjacent soft-bottom habitats. We used these data, obtained biannually (summer and spring) between 2012 and 2018, to estimate population parameters such as length-weight relationships (LWRs) for 28 species. Gender and ontogeny-based differences in LWR were determined in four species, while novel LWR information was generated for all other species.  相似文献   

18.
This study reports the length–weight relationships (LWR) of 20 fish species from the Pahang River, Maran district, Pahang, Malaysia. The river supplies fishes mainly for local consumption and is a principal body of water for freshwater aquaculture in Malaysia. A total of 12 LWR of fishes were unknown to FishBase, and five new maximum lengths of fishes were identified from the study.  相似文献   

19.
Length–weight relationships (LWR) were estimated for seven fish species from the Napo River and its main tributaries, Arabela and Curaray rivers, Amazon basin, Peru. A total of 652 specimens were sampled between 2012 and 2014 using seines and gillnets. This study reports new maximum total length for four species and new LWR and maximum total weight records for three and five species, respectively.  相似文献   

20.
The length-weight relationships (LWR) were estimated for five fish species from the Golfão Maranhense, Brazilian Amazon littoral region. Samplings were performed in August 2016, during the dry season, using trawl net with 6.0 m length by 3.0 m width (trawl mouth opening of 6.0 m2) and 1.0 cm mesh size between opposite knots. This study registers LWR for Anchoviella elongata and Gobioides broussonnetii and the estimated LWR for Aspredo aspredo and Aspredinichthys filamentosus covers a wider size range. Moreover, it is presented maximum length values for A. elongata and Sphoeroides greeleyi.  相似文献   

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