Length–weight relationships of the invasive topmouth gudgeon (Pseudorasbora parva) in ten lakes in the UK

The topmouth gudgeon (Pseudorasbora parva) is a species that is becoming invasive in UK waters. Few biological studies have been completed on the species in this extended range, resulting in sparse information in some aspects of their invasion biology. Regarding length–weight relationships, this is remedied in this study by providing data for 10 lake populations in the UK. Using fish length range 2.5–11.8 cm, values of a and b in the length–weight equation are provided. Values of b ranged between 2.76 and 3.32. Across all lakes, the relationship was W = 0.011L^3.03, with weight in grams and length (fork) in cm.     

Length–weight relationships and length–length relationships of 13 fish species in Rongcheng Bay,China

The present study provides the length–weight relationships (LWRs) of 13 fish species belonging to eight families that were collected in Rongcheng Bay, March 2009 to December 2014. The r² values ranged from 0.953 to 0.994 and values of b varied from 2.542 to 3.454. The study also describes the total length – standard length relationships (LLRs) for these fish species. This is the first record of length–weight and length–length relationships for the fish species in this area.     

Length–weight and length–length relationships of fish species from the Chi River,northeastern Thailand

The relationships of total length (TL), fork length (FL) and standard length (SL) are presented for four fish species and the relationships between TL and wet weight for 23 fish species from the Chi River in northeastern Thailand. All length–length relationships were linear (r² > 0.95). Slope (b) of the length–weight relationships showed values between 2.5073 and 3.4896.     

A review of length–weight relationships of fishes from freshwaters of Turkey

This paper presents 145 length–weight relationships gathered from the literature pertaining to 30 Turkish freshwater fish species belonging to six families. The value of the slope b ranged from 2.04 for Carassius carassius to 3.46 for Scardinus erythroptalmus. The mean value of b was 2.91 (SD = 0.305), which did not differ significantly from 3.0 (t‐test, P > 0.05). The median value of b was 2.95; 50% of the b values ranged from 2.68 to 3.14. The plot of log a vs b was used to detect outliers.     

Length–weight relationships and length at first maturity for nine fish species of floodplain lakes in Central Amazon (Amazon Basin,Brazil)

Length–weight relationships are presented for nine fish species from the floodplain lakes in the Central Amazon (Amazon Basin, Brazil). The parameter slope b values in the length–weight relationships ranged from 2.33 to 3.28 for grouped sexes, and from 2.7 to 3.61 for separated sexes. Differences between sexes were verified in three species. Sizes at first sexual maturation ranged from 9.14 to 23.97. This study provides a new reference for the length–weight relationships of six species.     

Biological traits of rare males in the population of Carassius gibelio (Actinopterygii: Cyprinidae) from Lake Pamvotis (north‐west Greece)

The gynogenetic population of Prussian carp Carassius gibelio in Lake Pamvotis (north‐west Greece) included a small percentage of males (2–3%). Cytogenetic analysis revealed heterogeneity of the population at the ploidy level: all females were triploid (modal chromosome number 156–162 chromosomes) while the males were either triploid (modal number 156–158 chromosomes) or tetraploid (modal number 200–214 chromosomes). Morphometric analysis revealed significant differences in body shape among these three groups. The males were more slender than females, while the triploid males could be discriminated from the tetraploid by the morphology of their caudal peduncle. The males attained a significantly lower asymptotic standard length (L_S) (25·04 cm) than females (29·75 cm) and had lower exponent b of the L_S and mass relationship. Under laboratory conditions, intraspecific crossings of C. gibelio males with females could give viable all‐female offspring; in comparison with goldfish Carassius auratus males, the fertility of the C. gibelio males was generally reduced but remained highly variable among individuals.     

Length–weight relationships of 16 fish species from the Tarim River,China

This paper reports the length–weight relationships of 16 fish species belonging to three families and ten genera from the Tarim River in China. Length–weight relationships for ten fish species were unknown to Fishbase, and new maximum lengths are given for six species. The r² values ranged from 0.972 to 0.995. Values of b varied from 2.79 to 3.49.     

A review of length–weight relationships of fish from the Segura River basin (SE Iberian Peninsula)

We present the relationships between fork length and total weight for 14 fish species from the Segura River basin (southeastern Spain): Barbus sclateri, Chondrostoma polylepis, Gobio lozanoi, Aphanius iberus, Micropterus salmoides, Lepomis gibbosus, Carassius auratus auratus, Cyprinus carpio carpio, Sander lucioperca, Gambusia holbrooki, Liza ramado, Mugil cephalus, Atherina boyeri and Pomatoschistus marmoratus. Significant length–weight relationships were found for all species. The values of the exponent b of the length–weight relationships ranged from 3.82 for Sander lucioperca to 2.59 for Micropterus salmoides.     

Length–weight relationships of wild fish captured at the mouth of Río Verde,Oaxaca, México and connected lagoons (Miniyua,El Espejo,Chacahua and Pastoría)

Length–weight relationships (LWR) were estimated for 34 fish species belonging to 25 genera and 17 families, specimens were collected near the mouth of the Río Verde, Oaxaca, Mexico. All r² values are statistically significant (P > 0.0001). The values of ‘b’ ranged from 2.55 and 3.3, within the usual range (2.5–3.5). This study provides the first LWR references for six species, and new maximum length records for eight species.     

Life history characteristics of an invasive cyprinid fish (Carassius gibelio) in Chimaditis Lake (northern Greece)

The life history characteristics of an invasive cyprinid fish, the Prussian carp (Carassius gibelio) were examined in Lake Chimaditis (northern Greece). The population is dominated by females that are able to reproduce gynogenetically. Fish samples were collected using trammel nets from August 2004 to July 2005. Their total length (TL) ranged between 21.9 and 37.0 cm. The length–weight relationship was W = 0.0336TL^2.81 (r² = 0.92, n = 600) and the mean Fulton condition factor exhibited monthly variation from 0.172 (May) to 0.186 (August). According to the annual growth marks present, the lifespan of the Prussian carp in Lake Chimaditis is 6 years. The growth parameters were estimated as L_∞ = 34.46 cm, K = 0.297 year^?1, t₀ = ?1.994 year. Absolute fecundity (F_A) ranged between 26 000 and 176 600 oocytes (mean = 66990) and relative fecundity between 78 and 251 oocytes per gram of total weight (mean = 158). Absolute fecundity increased exponentially with length (F_A = 0.286 × TL^3.66, r² = 0.66) and weight (F_A = 17.93 × W^1.36, r² = 0.73) of the fish.     

Cube law, condition factor and weight–length relationships: history, meta-analysis and recommendations

This study presents a historical review, a meta‐analysis, and recommendations for users about weight–length relationships, condition factors and relative weight equations. The historical review traces the developments of the respective concepts. The meta‐analysis explores 3929 weight–length relationships of the type W = aL^b for 1773 species of fishes. It shows that 82% of the variance in a plot of log a over b can be explained by allometric versus isometric growth patterns and by different body shapes of the respective species. Across species median b = 3.03 is significantly larger than 3.0, thus indicating a tendency towards slightly positive‐allometric growth (increase in relative body thickness or plumpness) in most fishes. The expected range of 2.5 < b < 3.5 is confirmed. Mean estimates of b outside this range are often based on only one or two weight–length relationships per species. However, true cases of strong allometric growth do exist and three examples are given. Within species, a plot of log a vs b can be used to detect outliers in weight–length relationships. An equation to calculate mean condition factors from weight–length relationships is given as K_mean = 100aL^b?3. Relative weight W_rm = 100W/(a_mL^bm) can be used for comparing the condition of individuals across populations, where a_m is the geometric mean of a and b_m is the mean of b across all available weight–length relationships for a given species. Twelve recommendations for proper use and presentation of weight–length relationships, condition factors and relative weight are given.     

Weight–length relationships of 36 fish species from the River Strymon system (northern Greece)

We present 54 weight–length relationships pertaining to 36 fish species, caught in the Greek part of the River Strymon system (northern Greece). The total weight (W) – total length (TL) relationships were estimated using the logarithmic form of the equation W = aTL^b. The exponent b ranged between 2.34 and 3.95, (mean ± SE: 3.16 ± 0.044). For 5 out of the 36 species weight–length parameters are presented for the first time.     

Morphological variations of an invasive cyprinid fish (Carassius gibelio) in lentic and lotic environments inferred from the body,otolith, and scale shapes

This study investigated the morphological variation of gibel carp Carassius gibelio collected from various water bodies in Türkiye. The fish samples were obtained from three dams (Karacaören-1, Karakaya, and Keban), two natural lakes (Beyşehir and Suğla), and a river (the Tigris River). The dimorphism in body shape was examined with geometric morphometrics, while elliptic Fourier analysis and shape indices were used to describe the variation in lapilli otoliths (hereafter “otoliths”) and scale shapes. The body of C. gibelio revealed higher variations, particularly in the body depth, snout length, caudal fin, and caudal peduncle, among different stations. Geometric morphometric analysis determined a streamlined body shape of C. gibelio in the Tigris River compared to other stations, while C. gibelio from the natural lakes had a deeper body shape. The body of C. gibelio exhibited a significant homogenous shape between the Beyşehir and Suğla lakes, providing the lowest Procrustes distance. The elliptic Fourier analysis revealed that the otolith shape varied significantly between all stations. However, the scale shape was remarkably similar among nearby areas such as Karacaören dam, Suğla, and Beyşehir lakes. These results evinced high degree of intra-population morphological variation in C. gibelio in response to prevailing environmental conditions that probably facilitate their successful establishment in a novel environment.     

Length–weight relationships of nine fish species from the Tongjiang section of the Songhua River,China

Length–weight relationships were evaluated for nine fish species from the Tongjiang section of the Songhua River in China. A total of 675 fish specimens were collected from 4 May to 29 October 2014. Length–weight relationships for six fish species (Romanogobio tenuicorpus, Leuciscus waleckii, Opsariichthys bidens, Microphysogobio amurensis, Pelteobagrus ussuriensis and Misgurnus mohoity) were new to FishBase in 2015, but the length–weight relationships of P. ussuriensis was studied by Ma in 2015. New data on M. mohoity is offered, and this study also shows new maximum total lengths for three fish species. The r² values ranged from .95 to .99. Values of b varied from 2.504 to 3.471.     

The relationship between body weight and natural mortality in juvenile and adult fish: a comparison of natural ecosystems and aquaculture

The relationship between body weight and natural mortality in juvenile and adult fish was analysed for different aquatic ecosystems: lakes, rivers, the ocean, and pond, cage and tank aquaculture systems. Mortality was modelled as a power function of weight, and the parameters b (exponent) and M_u (mortality at the unit weight of 1 g) estimated for fish in the six ecosystems, as well as within selected populations, species and families. At the ecosystem level, no significant differences in parameters were found between lakes, rivers and the ocean and a joint mortality-weight relationship for all natural ecosystems was estimated with parameters b=?0.288 (90% CL[?0.315, ?0.261]) and M_u=3.00 (90% CL[2.70, 3.30]) year^?1. Among the culture systems, mortality-weight relationships in ponds and cages were not significantly different and a joint relationship was estimated. The weight exponents of mortality in ponds/cages and tanks were very similar at about b=?0.43, and significantly more negative than in natural ecosystems. Mortalities at unit weight were significantly lower in tanks (0.91 year^?1) than in ponds/cages (2.24 year^?1), and both were significantly lower than in natural ecosystems. No systematic differences were found between the mortality-weight relationships determined for individual populations, species or families, and fish in the respective ecosystems. It is hypothesized that aquaculture mortality-weight relationships indicate the allometric scaling of non-predation mortality, which is therefore more strongly size dependent than predation mortality. If non predation mortality in natural ecosystems shows a similar scaling with body weight, then the allometric exponent of predation mortality must be less negative than that observed for total natural mortality. Implications of the established mortality-weight relationships for aquaculture and culture-based fisheries are discussed.     

Length–length and length–weight relationships of fish species from the Lake Eyre Basin,Australia

The Lake Eyre Basin in central Australia is one of the world's last unregulated dryland river systems. To facilitate future research in this area, the relationships between total length, standard length, and wet weight for 10 widespread, large‐bodied freshwater fish species are presented. All linear relationships were strong (r² > 0.90) and values of the exponent b of the length–weight relationships ranged from 2.786 to 3.336. These results provide novel baseline data for species in this area.     

Calcium Signaling in <Emphasis Type="Italic">Carassius</Emphasis> Cerebellar Neurons: Role of the Mitochondria

We studied the involvement of the mitochondria playing the role of a calcium store in the control of calcium exchange in cerebellar neurons of a fish species tolerant to hypoxia, crucian (Carassius gibelio). In our experiments we used an ionophore, CCCP, that blocked accumulation of calcium by the above organelles. The intracellular concentration of free Ca²⁺ ([Ca²⁺] _і ) was measured using a calcium-sensitive dye, Fura-2AM, and the microfluorescent technique. We found that cerebellar neurons of Carassius gibelio possess a well-expressed system clearing the cytoplasm from excessive Ca²⁺, and the mitochondria are actively involved in this process. Under conditions of suppression of the process of accumulation of calcium by the mitochondria under the action of CCCP, the amplitude of calcium transients increased by about 50%. In addition, the decay phase of depolarization-induced intracellular calcium transients was slowed down considerably. Therefore, our experiments are indicative of the significant role of the mitochondria in the control of calcium dynamics in cerebellar neurons of Carassius gibelio in the course of functional activity of these cells.     

Length–length and length–weight relationships of oilfish (Ruvettus pretiosus), escolar (Lepidocybium flavobrunneum), snake mackerel (Gempylus serpens), and longnose lancetfish (Alepisaurus ferox) from the Gulf of Mexico and the western North Atlantic Ocean

Oilfish, escolar, snake mackerel (order Aulopiformes, family Gempylidae), and longnose lancetfish (order Perciformes, family Alepisauridae) sampled from the western North Atlantic and the Gulf of Mexico were analyzed for length–weight and length–length relationships. These species are encountered as occasional bycatch of pelagic longline fisheries. The fish (161 specimens, 19.0–149.1 cm TL) were collected over a 3‐year period (January 2007–January 2010) from pelagic longline gear targeting swordfish and tuna. For each species, 95% confidence limits (CI) of parameters b and log a and regression coefficients (r²) were calculated for log‐transformed length–weight relationships. The length–weight parameter b for all species ranged from 2.881 to 3.358, with regression coefficients (r²) ranging from 0.75 to 0.98. Linear relationships between fork lengths, standard lengths, and total lengths were also calculated.     

Length–weight relationships of seven fish species from Guijiang River in Guangxi Region,China

Length–weight relationships (LWRs) were estimated for seven fish species from Guijiang River in Guangxi region, China. Fish samples were collected by electrofishing (CWB-2000P, China; 12 V import, 250 V export) and gill nets (length 12 m, height 0.8 m, mesh 10 mm) in January, April, July and October, 2015. The electrofishing was conducted about 2 km long within 2 hr, and ten gill nets were settled over night at each sampling site. All fish were identified and measured in the field immediately. All values for the allometric coefficient (b) of the length–weight equations were within the expected range (2.50–3.50). All values for the coefficient of determination (r²) were above .95 and thus the estimates can be considered reliable.     

Length–weight relationships and length at first maturity for fish species in the upper Miranda River,southern Pantanal wetland,Brazil

Length–weight relationships (LWR) were estimated for 17 species and total length at first maturity (L50) for three species of freshwater fishes from the Miranda River, southern Pantanal, Brazil. The b values were compared for some species in the Paraguay River basin with the northern (Cuiabá River) part of the basin; differences in length–weight relationships were significantly different for Pseudoplatystoma corruscans, P. reticulatum (syn. P. fasciatum). First references on L50 and LWR are presented for two and eight fish species, respectively, as well as the new maximum total length for two species.