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.     

Comparative oocyte morphology and fecundity of five characid species from São Francisco River basin,Brazil

The morphology of vitellogenic oocytes and the batch fecundity of five tropical forage species belonging to the family Characidae, were studied in 104 late‐maturing ovaries. Significant morphological differences between vitellogenic oocytes and ovarian follicles were found. The lowest batch fecundity values were recorded in Hemigrammus marginatus (480 ± 163) and Orthospinus franciscensis (1701 ± 562), which were the smaller species in terms of total length, body weight and oocyte diameter. The highest batch fecundity value was observed in Tetragonopterus chalceus (8384 ± 3944) having the highest GSI and oocyte diameter. Batch fecundity and gonad weight was highly correlated followed by body weight and total length. Relative fecundity was estimated per unit total length, body weight and gonad weight. The wide variation in fecundity observed between the specimens and the species analysed is possibly related to the multiple spawning reproductive strategy of these fishes. Since T. chalceus have higher values of batch and relative fecundity, it is concluded that this species has a higher reproductive potential than the other forage species studied.     

Length‐weight relationship of stingrays in Kuala Selangor,Malaysia

Length‐weight relationships of three sympatric species of stingrays from a coastal mudflat, Malaysia were estimated. A total of 290 individuals (150 Himantura walga, 78 Dasyatis bennetti, and 57 Dasyatis zugei) were sampled using barrier net, gill net and beam trawl. The length‐weight relationship based on disc length and width generally showed positive allometric growth (b > 3) for all species. This study reports the first findings regarding the length‐weight relationships of these stingray species in Malaysian waters.     

Relationships between fish size and otolith size of four bathydemersal fish species from the south eastern Arabian Sea,India

The objective of this study was to estimate a prey body size from the hard parts (e.g. otoliths) of a fish species frequently found in the guts of predators. Length–weight relationships between otolith size (length, height, weight and aspect ratio) and fish size (total length and weight) were determined for four fish species captured in the Arabian Sea by bottom trawl (2015 survey on‐board FORV Sagar Sampada, 200–300 m depth), off the west coast of India: Psenopsis cyanea, Pterygotrigla hemisticta, Bembrops caudimacula and Hoplostethus rubellopterus. No significant differences were noted between the size of the left and right otoliths (t test) in any of the four species. The length–weight relationship of the otolith in all four species showed a negative allometric growth pattern (t test, p < .05). The data fitted well to the regression model for otolith length (OL), otolith height (OH) and otolith weight (OW) to total length (TL) and total weight (TW). Results showed that these relationships are a helpful tool in predicting fish size from the otoliths and in calculating the biomass of these less‐studied fish species during feeding studies and palaentology.     

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 weight‐length relationship of fish species found in the tidal creeks of the Amazon estuary,northern Brazil

The present study estimated the a and b parameters of the weight‐length relationship of five fish species that inhabit the tidal creeks of islands in the Amazon estuary: Colomesus asellus, Geophagus proximus, Lithodoras dorsalis, Pseudauchenipterus nodosus, Pachypops fourcroi. The species were collected quarterly between October 2013 to July 2014 using block nets made from 20 mm mesh size. The b coefficient of the regression of the weight on the total length of these species ranged from 2.71 to 3.14. These are the first reference on the weight‐length relationship for three species and the new maximum length recorded for two species.     

Biometric relationships between body and otolith measurements in nine demersal fishes from north‐eastern Tasmanian waters,Australia

Relationships between fish and otolith measurements were analyzed in nine demersal fishes from the north‐eastern Tasmanian waters: Foetorepus calauropomus, Trachurus declivis, Parequula melbournensis, Neosebastes scorpaenoides, Platycephalus aurimaculatus, Platycephalus bassensis, Platycephalus conatus, Lepidotrigla mulhalli and Lepidotrigla vanessa. The values of exponent b from the relationships between fish weight and fish total length, total length and otolith length, total length and otolith width, and fish weight and otolith length were estimated. All above relationships were statistically significant. The analysis of covariance (ANCOVA) was used to test the effect of the categorical factor of species in the fish length and otolith length relationship. Significant differences in fish length and otolith length relationship between species were highlighted in both gurnards and flatheads. Results from this study will provide novel information on quantitative biometric relationships between body and otolith measurements of fish species in Australian waters.     

Length–weight and length–length relationships of four native fish species from the Yalong River,China

Length‐weight and length‐length relationships were estimated for four native fish species from the Yalong River and its tributaries, China. A total of 976 specimens were collected monthly using trap nets and electric fishing in May 2013 and July 2015 to February 2016. This study presents the first references on LWRs (length–weight relationships) and LLRs (length–length relationships) for three species (Gymnocypris firmispinatus, Paracobitis variegatus and Euchiloglanis kishinouyei). Moreover, maturation length, absolute fecundity and predominant food items for the four species were also described in the study.     

Lesser Sandplover,Charadrius mongolus,in Turkey

Sagittal otoliths are widely used to determine taxon, age and size of the teleost fishes, and are useful tools for studies of prey-predator relationships, population dynamics and ichthyo-archaeology. They can also be used to estimate the size of the prey. We examined the relationships between otolith measurements (length, height and weight) and fish size (total length and weight) for two species of Argentinidae (Argentina sphyraena and Glossanodon leioglossus) from the Southern Aegean Sea, Turkey. Length, height and mass of sagittae were shown to be good indicators for the length and weight of fish in both species. Glossanodon leioglossus has relatively larger sagittae than Argentina sphyraena. Linear and exponential functions provided the best fit for relations between otolith and fish measurements. No significant differences were found between left and right otolith sizes.     

Length–weight relationships for five fish species from Jingpo Lake,Heilongjiang, China

In this study the length–weight relationships for five fish species from Jingpo Lake in China belonging to three families and five genera were analyzed. A total of 368 specimens were used to estimate the relationship parameters. One species (Leuciscus waleckii) had no previous LWR estimate in FishBase.     

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 relationships of two sympatric species (Knipowitschia byblisia Ahnelt, 2011 and K. caunosi Ahnelt, 2011) in Köycegiz Lake,Turkey

This study provides basic information on length–weight relationships for Knipowitschia byblisia Ahnelt, 2011 and Knipowitschia caunosi Ahnelt, 2011, two endemic species of Köycegiz Lake Basin (Southern‐West of Turkey). Samplings were carried out seasonally from 2014 to 2015 by means of beach seine nets with mesh sizes from 10 to 35 mm. A total of 343 individuals from the two fish species were examined, with more specimens belonging to K. byblisa (90.4%). The total length–weight relationships were calculated as: W = 0.0054 TL^3.384for K. byblisia and W = 0.0058 TL^3.417for K. caunosi, respectively.     

Length–weight relationships of 10 freshwater fish species from an intermittent river basin,semi‐arid region,Brazil

The length–weight relationships for 10 freshwater fish species from an intermittent river basin in a semi‐arid region of Brazil were analyzed. Specimens were caught using a dragnet (3.5 × 2.5; stretched mesh size 5 mm) during running and pool phases from January to November 2015. The specimens were measured for total length and weight. Previously unavailable in FishBase, the detailed length–weight relationships of Compsura heterura, Phenacogaster calverti, and Serrapinnus piaba are reported for the first time. All fish collected presented total lengths (TL) lower than the maximum reported in FishBase.     

Length‐weight and length‐length relationships of two tropical fish Secutor megalolepis (Mochizuki & Hayashi, 1989) and Rhabdamia gracilis (Bleeker, 1856) from Sabah,Malaysia

Length‐weight relationships (LWRs) and length‐length relationships (LLRs) for two tropical fish species from Marudu Bay, Sabah were studied. Specimens were caught with the traditional ‘Bagan net’ fishing gear from October 2012 to September 2013, using the light trap method. The maximum total length for Rhabdamia gracilis (7.4 cm) reported in this study is a new record for this species. No information regarding length‐weight relationships was reported previously in FishBase for either Secutor megalolepis or Rhabdamia gracilis.     

Length–weight relationships for six fish species from the middle of the Yalu Tsangpo River,China

This paper reports the length–weight relationships for six fish species belonging to the Cyprinidae from the middle of the Yalu Tsangpo River in China. Samples were obtained by electroshock and drift net fishing techniques (mesh size 2 cm × 3 cm; 200 m net length) in April and September to October 2014. Length–weight relationships estimates for these species were not available in FishBase. A total of 737 specimens were used to estimate the a and b parameters. New maximum total lengths are also reported for six species. The r² values range from 0.98 to 0.99. Values of b vary from 2.88 to 3.19.     

Seasonal changes in fish catch and environmental variables in a large Tropical Lake,Volta, Ghana

Fish species assemblage and selected environmental variables were monitored in Lake Volta from September 2014 to August 2016 to determine seasonal variability in species composition, catch and environmental variables that determine the structure of the fish community. A total of 1,557 individual fish belonging to 41 species, 25 genera and 13 families were recorded. The important fish species with respect to frequency of occurrence, abundance and weight, respectively, were as follows: Chrysichthys (100%; 43.03%; 17.93%), tilapias (100%; 28.97%; 17.86%), Alestes (100%; 14.13%; 32.10%) and Bagrus (91.67%; 5.65%; 12.80%) in that order. The composition of fish species and their temporal variation in experimental catches were similar to that of commercial catches. There were no significant differences (p > 0.05) in species abundance, weight and diversity indices between the dry and wet seasons. The modal class of length frequency distribution of the dominant species in the catch, Chrysichthys, reduced from 125 mm in 2006 to 95 mm in the current study indicating overfishing. Environmental variables considered showed little variation and within optimal ranges for fish survival and did not differ significantly between seasons. Canonical Correspondence Analysis showed that environmental variables explained 43.30% of the variation in species abundance with Lake water level, nitrite‐nitrogen and total dissolved solids being the main environmental factors influencing the structure of the fish community.     

Length–weight relationships of five fish species from the streams of Maoershan National Forest Park,Heilongjiang, China

In this study the length–weight relationships of five fish species belonging to four families and five genera were analyzed from the streams of Maoershan National Forest Park in China. A total of 221 specimens were used to estimate the relationship parameters. These species (Lethenteron reissneri, Cobitis granoei, Misgurnus mohoity, Rhynchocypris percnurus and Perccottus glenii) had no previous estimate in FishBase.     

Length–weight relationships of six tropical fish species from Chilika Lagoon,India

The length weight relationships (LWRs) of six tropical fish species from Chilika Lagoon, India were studied. Specimens were caught using a wide range of fishing gear operated in the lagoon from January to December 2014. The fresh specimens were measured for total length and weight, then dissected and the sex confirmed. Previously unavailable in FishBase, the detailed LWRs of Daysciaena albida, Eleutheronema tetradactylum, Etroplus suratensis and Mystus gulio are reported for the first time. Maximum total lengths reported for Nematalosa nasus and Osteogeneiosus militaris in this study are new records for these species. The existence of a differential growth between male and female O. militaris was confirmed, which was not known earlier.     

Length–weight and length–length relationships of 26 fish species from the Yiluo River,a tributary of the Yellow River,China

From February to October 2016, a total of 9,754 fish specimens were collected from the Yiluo River, a tributary of the Yellow River, China's second longest river. Based on these samples, length–weight relationships (LWRs) and length–length relationships (LLRs) were estimated for 26 species. Among these data, LWRs for 1 species, LLRs for 11 species, and maximum total lengths for six species were not previously recorded in FishBase. The a values of the LWRs varied between 0.0019 and 0.0116, and b values from 2.805 to 3.883. All regressions for LWRs and LLRs were highly significant (p < .001). These results will be useful for sustainable management and conservation of the fish resources in the Yiluo River and the Yellow River ecosystem.     

DIASPORE SIZE,SHAPE, AND FALL BEHAVIOR IN WIND-DISPERSED PLANT SPECIES

Seeds and fruit of 38 anemochorous species were dropped in still air to simulate their descent under natural conditions. Fall rate and lateral distance were recorded as indices of wind-borne dispersal capability. Differences in fall rates among plumed species were dependent on interspecific variation in diaspore weight and plume area, while fall rates of winged species were strongly differentiated by contrasting wing shapes. In Acer platanoides and Asclepias syriaca, representing wing and plume architectures, respectively, the range of diaspore weight was artificially extended by removing embryos or adding lead weights. In both of these species, rate of descent of altered diaspores was controlled by weight relative to wing or plume area. The wing morphology of A. platanoides showed lower fall rates than the plumed A. syriaca above 45 mg, while the plume morphology of A. syriaca achieved lower fall rates below this weight. Compared with wide variation in diaspore weight, members of the Compositae showed relatively low variation in plume loading (diaspore weight/plume area) and fall speed. These observations suggest functional and phyletic constraints on diaspore architecture. Such constraints may limit evolutionary change in diaspore size and performance.