Length‐weight and length‐length relationships of four Alosa species along the southern Caspian Sea coast

This study investigates length‐weight and length‐length relationships of four shad species (Alosa braschnikowi, Alosa caspia, Alosa kessleri, and Alosa saposchnikowii) captured on the southern Caspian Sea coast of Iran. The relationship of total length (TL), fork length (FL) and standard length (SL) and the relationship between total length and body weight are presented.     

Length‐weight and length‐length relationships of the genus Alosa (Clupeoidei: Clupeiformes: Clupeidae) along the southern Caspian Sea coast

Length–weight (LWR) and length–length (LLR) relationships were estimated for four shad species of the genus Alosa, reported from along the southern Caspian Sea coast, north of Iran in a study from March 2014. Two of these species are endemic to the Caspian Sea. The length–weight parameter b for these species ranged from 2.99 to 3.24, with regression coefficients (r²) ranging from 0.91 to 0.99. All LLRs were highly significant (r² > 0.96).     

Length–weight relationships for six fish species in Iskenderun Bay (Eastern Mediterranean Sea coast of Turkey)

The length–weight relationships (LWRs) were estimated for six non‐indigenous fish species, namely, Apogon smithi (Kotthaus, 1970); Ostorhinchus fasciatus (White, 1790); Pomadasys stridens (Forsskål, 1775); Champsodon capensis Regan, 1908; Torquigener flavimaculosus Hardy & Randall, 1983; and Tylerius spinosissimus (Regan, 1908) from Iskenderun Bay, eastern Mediterranean Sea. Their length–weight relationship b values ranged from 2.902 to 3.501, and all regressions were found to be significant for all six species (P < 0.001). This study is the first reference on length–weight relationships for these six non‐indigenous fish species from the Eastern Mediterranean Sea coast of Turkey.     

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.     

Length–length and length–weight relationships for eight drum species in southeastern Louisiana

Length–length and length–weight relationships can vary temporally and spatially, so it is imperative that accurate estimates of these relationships are available. Total length–standard length (TL‐SL) and standard length–total weight (SL–TW) relationships were calculated for eight species of drum (Sciaenidae) occurring in estuaries of southeastern Louisiana. Data were derived from monthly trawl, beach seine, and gillnet collections taken in and around Lake Pontchartrain between 2000 and 2012. Overall TL–SL relationships (ignoring the month) were found for seven species and overall SL–TW relationships were found for eight species. The strong r² values (all > 0.950, except for one instance) indicate that these relationships are robust and will be appropriate for use by scientists managing these species.     

Length–weight and length–length relationships of eight endemic Aphanius species from Turkey

Length–weight and length–length relationships were assessed for eight endemic Aphanius species from Turkey. This study provides a new reference on length–weight and length–length relationships and new maximum sizes for all species examined.     

Length–weight and length–length relationships of three Blenny species from the Persian Gulf and the Gulf of Oman

The present study provides the length–weight and length–length relationships information (LWR & LLR) for three Blenny species; Antennablennius adenensis from the coast of Larak Island in the Persian Gulf and Istiblennius pox and Omobranchus mekranensis, which were captured in the coasts of Chabahar city in the Gulf of Oman, Iran. Total length (TL) and standard length (SL) were determined as well as weight. Specimens were collected occasionally in summer 2017 and winter 2018 by Hand net. The length–weight parameter b for these species was 2.84, 3.29 and 3.06 respectively with a high coefficient of determination (r² ≥ 0.95). All LLRs were highly correlated (r² > 0.99). All three species had no previous report for LWR and LLR estimates in FishBase.     

Length–weight and length–length relationships for three endemic Pseudophoxinus species in Turkey

Length–weight and length–length relationships are presented for three endemic Pseudophoxinus species in Turkey. This study provides the first references for these relationships in the species examined.     

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.     

Age and growth of the Black Sea turbot, Psetta maxima (Linneaus, 1758) (Pisces: Scophthalmidae), estimated by reading otoliths and by back-calculation

Age and growth of the Black Sea turbot, Psetta maxima, were determined from a total of 1445 individuals collected along the eastern Black Sea coast between 1990 and 1996. Age was estimated by interpreting growth rings in whole and broken sagittal otoliths. The former method underestimated the age over 5 years, and a maximum age of 11 years was observed by the latter. Marginal increment analysis clearly showed that a single annulus is formed in early summer each year. Growth in length differed between sexes, and females attained a larger size than males at the same age. No significant difference was found between the mean observed total length (TL), the back‐calculated TL derived from radius measurements and the TL estimated from otolith size–fish size relationship. The von Bertalanffy growth parameters estimated by the length‐at‐age data were: L_∞ = 96.24 cm; K = 0.119 year^?1; t₀ = ?0.01 year for the entire population.     

Length–weight and length–length relationships of three Clupeonella species (Clupeidae) from the Caspian Sea

This study investigated length–weight and length–length relationships of three Clupeonella species: C. caspia, C. engrauliformis and C. grimmi captured in the southern Caspian Sea, Iran. Using a lantern net, 206 specimens were collected from July to August 2016. Presented for two of the species are the length–weight and the length–length relationships as well as the first reference on length–weight and length–length relationships for C. caspia in its distribution range.     

Length–weight relationships of fish species caught by bottom trawl in Jiaozhou Bay,China

Length–weight relationships (LWRs) were estimated for 31 fish species caught by bottom trawl surveys in Jiaozhou Bay on the west coast of the south Yellow Sea. Specimens were collected from September 2008 to August 2009 at monthly intervals. This study presents the first reference on LWRs for 15 of these species and new records of maximum total length for two species. Most of the b values fell within the expected range of 2.5–3.5. The mean value of b was 3.094 ± 0.064 (95% CL), which was significantly larger than 3.0, indicating a slight but significant tendency towards positive allometric growth in most of the fishes. Effects of the sex, season and growth phase were taken into account in this study. Results showed significantly different relationships between males and females in three of the species. Four species were found to have highly significant seasonal differences in the regression slope of b. Two different growth stanzas were detected using the double‐logarithmic plot of body weight vs total length for three species. The finding that the absolute residuals of b from 3.0 would become smaller with the increase in length‐range used was confirmed in this study.     

Length–weight and length–length relationships of two goby species,Neogobius caspius (Eichwald, 1831) and Proterorhinus nasalis (De Filippi, 1863) from the southern Caspian Sea

The present study provides the length–weight (LW) and length–length (LL) relationships for two goby species, Neogobius caspius and Proterorhinus nasalis, which were captured in the southern Caspian Sea. Total length (TL) and standard length (SL) were determined as well as weight. Specimens were collected monthly from September 2014 to August 2015 by beach seine (mesh size 10 mm). The LW parameter b for these species was 3.17 and 2.99, respectively, with a high coefficient of determination (r² > .95). All LLRs were highly correlated (r² > .97). Both species had no previous LWR and LLR estimates in FishBase.     

Reanalysis of long‐term surveys on the ecology and biology of mud skate (Rhinoraja taranetzi Dolganov, 1985) in the northwestern Pacific (1993–2002)

Based on data sampled in 1992–2002, the occurrence, spatial distribution, bathymetry, bottom temperatures preferences, size composition, feeding, and some features of reproductive biology of mud skate Rhinoraja taranetzi in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka are considered. Throughout the year, the mud skate was most abundant in the central part of the study area, from the coast of Onekotan Island to the southern tip of Kamchatka peninsula. The proportion of this species in bottom trawl catches in different seasons has changed slightly. However, maximum catch occurred in September–December. In April–May mud skates occupied shallower depths (mean 230–270 m), moving deeper in the summer period (mean 340–390 m). In December–March the skate occurred at lower bottom temperatures (mean 0.8–1.6°C) whereas the rest of the year it inhabited warmer waters with mean bottom temperatures of 2.5–3.1°C. Throughout the year decreasing body weight with depth was observed, indicating that adult and juvenile mud skates inhabit different depths. Total length of mud skates in catches ranged from 17 to 70 cm with a mean of 51.71 cm. Relation between total length (TL, cm) and body weight (W, g) was: W = 0.0029TL^3.1614 (r² = 0.978). Males were more abundant among small skates (<30 cm) only, whereas females predominated among larger skates (>30 cm) comprising about 70% in 60–70 cm length class. Female mud skates were longer and heavier than males (mean length 56.9 vs 51.2 cm and mean weight 1206 vs 807 g, respectively). This species is considered to be benthophagous, consuming mostly amphipods (34.9% by weight), polychaete worms (27.6%), decapod crustaceans (12.7%), and fishery discards (13.9%). Small skates (20–40 cm) fed mostly on amphipods (85.4%); medium‐sized (40–60 cm) ate amphipods (40.2%), polychaetes (29.1%) and decapods (19.3%); the largest individuals (>60 cm) consumed fishery offal (27.9%) and less amphipods (26.6%) and polychaetes (27.7%). Preliminary data on the maturation of the species in the western Bering Sea showed that males and females become mature at lengths above 61 cm TL.     

Length–weight and length–length relationships of three fish species (Cyprinidae) from Chahnimeh reservoirs,Zabol, in eastern Iran

Length–weight (LWR) and length–length (LLR) relationships was estimated for three fish species collected in Chahnimeh reservoirs located in the city of Zabol, Iran. The values of the parameter slope (b) in the length–weight relationship were determined 2.45 for Crossocheilus latius, 2.97 for Schizocypris altidorsalis and 3.14 for Schizothorax zarudnyi. The relationships between TL, FL and SL were all linear (for all cases: r² > 0.93).     

Length–weight and length–length relationships of the bluefin tuna,Thunnus thynnus L., in the Turkish part of the eastern Mediterranean Sea

This study describes length–weight (LWR) and length–length relationships (LLR) of bluefin tuna (BFT), Thunnus thynnus, in the eastern Mediterranean (Levantine Sea). Fulton’s condition factor (K) was also calculated for each standard length class for both sexes. A total of 363 specimens, 175 males and 188 females, were caught by purse‐seine from late winter to early summer 2003 off Antalya Bay, Turkey. Fork length values of 175 BFT males were between 114 and 250 cm with an average of 159.3 cm ± 2.14, and between 116 and 256 cm with an average of 163 cm ± 2.26 in 188 females. LWRs indicated positive allometric growth in both males and females. The coefficient b ranged from a minimum 3.32 for males to a maximum of 3.35 for females. Results indicated that the LLRs were highly correlated (r² > 0.99, P < 0.001). K values ranged from 1.45 to 2.11 (mean: 1.56 ± 0.12) in males and from 1.43 to 2.14 (mean: 1.69 ± 0.06) in females.     

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.     

Length–weight and length–length relationships of 11 fish species from the Sea of Okhotsk

Estimated length–weight relationships are presented for 11 marine fish species representing six families, found above the continental shelf and in the pelagial of the Okhotsk Sea. A total of 13,841 specimens were caught by trawls that were equipped with a 1.0 by 1.2 cm mesh webbing inset. The period between 1974 and 2015 comprised mostly spring and autumn months. All length–weight relationships were highly significant (r² ≥ .95) on a log scale. None of the species had previous length–weight estimates, and two species had no previous length–length estimates in the FishBase.     

Length–weight and length–length relationships for three Sillago species (Sillaginidae) from the Persian Gulf

This study investigates length–length and length–weight relationships of three Sillago species [Sillago arabica McKay & McCarthy (Memoirs of the Queensland Museum, 27, 1989, 551), Sillago attenuata McKay, 1985 and Sillago sihama (Forsskål, 1775)] captured in the Persian Gulf, Iran. A collection of 220 specimens was captured from August 2015 to January 2016 by cast net (mesh size: 10 mm) and beach seine (mesh size: 15 mm). The relationships of total length (TL) and standard length (SL) and the relationships between total length and body weight are given. This study presents the first reference on LWRs for two of the species (S. arabica and S. attenuata) in their range of distribution.     

Length–weight relationships for four stingray species from the tropical Atlantic Ocean

This study provides separate length–weight relationships (LWRs) for males, females and pooled individuals for four stingray species (Dasyatis guttata, Dasyatis marianae, Gymnura micrura, and Rhinoptera bonasus) found in the tropical Atlantic. The specimens were sampled monthly between April 2009 and February 2011 along the coast of Alagoas, northeastern Brazil, using different fishing gear. For three species, the LWR parameters are reported for the first time, including D. marianae, an endemic species.