scholarly journals Population structure and reproduction of a migratory fish Leporinus piau (Characiformes: Anostomidae) in a semiarid tropical reservoir, Brazil

2016 ◽  
Vol 64 (4) ◽  
Author(s):  
Darlan Dantas Alves de Araújo ◽  
Jônnata Fernandes de Oliveira ◽  
Rodrigo Silva da Costa ◽  
José Luís Costa Novaes
Keyword(s):  
Population Structure ◽  
Standard Length ◽  
Water Levels ◽  
Maturity Stage ◽  
Migratory Fish ◽  
Initial Development ◽  
Relationship Length ◽  
Length Relationship ◽  
First Maturity ◽  
Migratory Fishes

Migratory fishes have been seriously impacted by the building of reservoirs and because of the negative effects of these projects such as the interruption of migratory routes, reduction or elimination of spawning/feeding areas, and initial development can influence the population structure the migratory fishes, resulting in reduction in abundance. Leporinus piau is migratory fish widely distributed in the watersheds of the Brazilian semiarid             and it is of importance for artisanal and sport fishing. The goal of the study was to evaluate the population structure and reproductive dynamics of the migratory species Leporinus piau in the Pau dos Ferros Reservoir, which is located in the semiarid region of Brazil. The CPUE, length structure, length-weight relationship, length at first maturity, sex ratio, gonad development and IGS were analyzed. Collections were performed quarterly between February 2011 and November 2012 using gillnets. The captured fish were counted; the standard length (cm) and total weight (g) were measured, and dissected to determine the sex and gonad maturity stage. The rainfall and reservoir water levels were recorded, and their correlations with the reproductive period and CPUE were analyzed. A total 549 individuals were captured. The average CPUE varied between 0.0259 individuals/m2*h (May/2011) and 0.0008 individuals/m2*h (August/2012), and significant differences were observed; however, significant correlations were not observed between rainfall and reservoir levels. The standard length varied between 5.9 cm and 20.7 cm, and the weight varied between 4.16 g and 271.5 g. A histogram analysis revealed that the 5-10 cm standard length class was the most abundant for juveniles and that the 10-15 cm class was the most abundant for adult females and males. The weight-length relationship was best fit by the equation log10Wt = -1.57711 + 3.00707 Log10 Ls, and the species presented isometric growth. The estimated length at first maturity was 12.76 cm. A total of 148 males and 82 females were collected (1.81:1, M:F), and these values were significantly different. The highest GSI was observed in February 2011 for both females (10.69) and males (5.72), and the GSI was significantly and positively correlated with rainfall. We concluded that the L. piau population is established in the reservoir and found that its reproduction period occurred during the rainy season between February and May.

scholarly journals Allometric growth patterns in hatchery-reared larvae of the catfish Lophiosilurus alexandri (Pisces: Pseudopimelodidae)

2014 ◽  
Vol 66 (1) ◽  
pp. 284-288 ◽  
Author(s):  
R.J. Guimarães-Cruz ◽  
V.C. Veloso-Júnior ◽  
N.G. Sales ◽  
D.A.A. Oliveira ◽  
J.E. Santos
Keyword(s):  
Standard Length ◽  
Growth Analysis ◽  
Body Height ◽  
Growth Patterns ◽  
Head Length ◽  
Allometric Growth ◽  
Positive Relation ◽  
Initial Development ◽  
Eye Diameter ◽  
Head Height

The aim of the present study was to characterize the relationships that occur between morphometric variables of larvae of Lophiosilurus alexandri Steindachner, 1876 through their allometric growth analysis. Total length, head length and body height were correlated with standard length, head height and body height, as well as eye diameter and head height with head length. The results revealed allometric positive relation during the initial development, where the b coefficient varied between 1.10 and 2.81. The variable pre-anal distance in relation to the standard length and the snout length in relation to the head length revealed an allometric negative relation, where the b coefficient was 0.85 and 0.94, respectively.

scholarly journals Inter-annual variations in the abundance of young-of-the-year of migratory fishes in the Upper Paraná River floodplain: relations with hydrographic attributes

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 649-660 ◽  
Author(s):  
HI. Suzuki ◽  
AA. Agostinho ◽  
D. Bailly ◽  
MF. Gimenes ◽  
HF. Júlio-Junior ◽  
...  
Keyword(s):  
Water Levels ◽  
Migratory Species ◽  
River Floodplain ◽  
Annual Variations ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Young Of The Year ◽  
Paraná River Floodplain ◽  
Migratory Fishes

In this study, we identified and characterized the hydrographic attributes related to the success of recruitment of migratory fishes in the Upper Paraná River floodplain. To achieve our objectives, we analyzed inter-annual variations in the abundance of young-of-the-year (YOY; index of recruitment) of six migratory species and their relations with hydrographic attributes. Recruitment was related to the intensity, duration (in different fluviometrical levels), elasticity, number of pulses, greater uninterrupted overflow and delay of the floods (all obtained using the PULSO software). Collections of fish were conducted in the period between January 1987 and November 2007 in distinct environments (river channels, secondary channels and connected and disconnected floodplain lakes) distributed along three subsystems (Paraná, Baía and Ivinheima). Relations between recruitment and the attributes of interest were determined through analysis of covariance. In the studied period, the highest abundances of YOY were registered in 2007, followed by 1992, 1993, 2005 and 1988. The abundance of YOY was positively correlated with an intensity of high water levels (potamophase) and the duration of potamophase 1 and negatively with the duration of low water levels (limnophase) and a delay of flood. Higher hydrometric levels (540 and 610 cm for Paraná and 325 and 450 cm for Ivinheima) and greatest uninterrupted overflow presented different relations (significant interactions) among subsystems, but all with positive effects on recruitment. Results evidenced that recruitment responded better when floods started in January with potamophase intensities above 610 cm and water levels above 450 cm over a period of 50 days and repeated every two years (or > 610 cm for 38 days and repeated every two or three years). Therefore, artificial control of the floods at intervals of two or three years by manipulating the discharge of dams located upstream from the floodplain in a way that promotes potamophases with the potential to ensure recruitment of migratory species may become an important tool for conservation of migratory fish species in the floodplain.

scholarly journals Polyphasic growth in fish: a case study with Corydoras paleatus (Siluriformes, Callichthyidae)

2016 ◽  
Vol 106 (0) ◽  
Author(s):  
José R. S. Barradas ◽  
Isabel S. Lermen ◽  
Gabriel G. Larré ◽  
Thaís P. Martins ◽  
Nelson F. Fontoura
Keyword(s):  
Growth Pattern ◽  
Rio Grande ◽  
Allometric Growth ◽  
Rio Grande Do Sul ◽  
Power Equation ◽  
Length Relationship ◽  
First Maturity ◽  
Changing Rate ◽  
Specific Length

ABSTRACT A weight-length relationship was established for Corydoras paleatus (Jenyns, 1842) (Siluriformes, Callichthyidae) (n=596) from samples taken in November-December 2009 and March-April 2010, in Pinguela Lagoon (29°46'57"S; 50°11'16"W), Rio Grande do Sul, Brazil. The species showed a polyphasic allometric growth pattern, each stanza described by an independent power equation controlled by a switch function: W = a1Lb1 ∙ (1 + eRsc ∙ (L-SCP))-1 + a2Lb2 ∙ [1 - (1 + eRsc ∙ (L-SCP))-1] ; where W is the expected weight for a specific length L, a1 and a2 are the proportionality coefficients for stanzas 1 and 2, b1 and b2 are the allometric coefficients for stanzas 1 and 2, Rsc is the stanza changing rate for the switch function and SCP is the stanza changing point for the switch function. The stanza changing point was estimated as 5.28 cm, corresponding with the length at first maturity for this species Lmat (5.29 cm). Our data suggest that a complex growth pattern can be in nature, and perhaps not often identified because trends are obscured by natural variability.

scholarly journals ASPEKBIOLOGI IKANKURISI (Nemipterus japonicus) DI PERAIRANTELUKBANTEN

2016 ◽  
Vol 8 (1) ◽  
pp. 21
Author(s):  
Selvi Oktaviyani ◽  
Mennofatria Boer ◽  
Yonvitner Yonvitner
Keyword(s):  
Fisheries Management ◽  
Average Length ◽  
Maturity Stage ◽  
Allometric Growth ◽  
Fishing Activity ◽  
Fish Resources ◽  
Nemipterus Japonicus ◽  
Males And Females ◽  
Biological Aspects ◽  
First Maturity

<p>Ikan kurisi (<em>Nemipterus japonicus</em>) merupakan salah satu sumber daya ikan ekonomis penting di Perairan Teluk Banten dan banyak didaratkan di Pelabuhan Perikanan Nusantara (PPN) Karangantu, Banten. Intensitas penangkapan yang tinggi akan menyebabkan tangkap lebih (<em>overfishing</em>), sehingga mengancam kelestarian ikan kurisi. Penelitian ini bertujuan untuk mengetahui beberapa aspek biologi ikan kurisi di Perairan Teluk Banten, seperti struktur ukuran panjang, rasio kelamin, hubungan panjang berat, tingkat kematangan gonad, ukuran panjang rata-rata tertangkap (Lc) dan ukuran pertama kali matang gonad (Lm). Informasi yang diperoleh dapat menjadi bahan pertimbangan dalam kegiatan pengelolaan perikanan. Lokasi pengambilan contoh dilakukan di Pelabuhan Perikanan Nusantara (PPN) Karangantu, Banten dari bulan Mei hingga Agustus 2012. Hasil penelitian menunjukkan bahwa ukuran panjang total ikan kurisi<em> </em>berkisar antara 98 dan 211 mm. Perbandingan kelamin jantan dan betina dalam keadaan seimbang dan memiliki pola pertumbuhan allometrik negatif yang menunjukkan pertumbuhan panjang lebih cepat dibandingkan pertumbuhan beratnya. Lebih dari 50% ikan-ikan yang diamati baik jantan maupun betina selama bulan pengamatan belum matang gonad (<em>immature</em>).  Ukuran pertama kali matang gonad adalah 196 mm sedangkan ukuran panjang rata-rata tertangkap adalah 146 mm. Banyaknya ikan yang tertangkap dalam ukuran kecil (kurang dari panjang pertama kali matang gonad) akan mengganggu kelestarian ikan kurisi.</p><p><em><br /></em></p><p><em>Japanese threadfin bream </em>(Nemipterus japonicus<span style="text-decoration: underline;">)</span><em> is one of the most important economical fish resources in the Gulf of Banten and many landed at Archipelago Fishing Port (PPN) of Karangantu. High intensity of fishing activity can cause an overfihing, and threat sustainability of japanese threadfin bream. The research was aimed to determine some biological aspects of japanese threadfin bream in the Gulf of Banten, such as structure of the length, sex ratio, length-weight relationship, gonad maturity stage, the average length of captured (Lc) and the length of first maturity (Lm). It is believed that the collected information can be taken into consideration in the fisheries management activities. The sample was collected at PPN Karangantu, Banten from May to August 2012. The result showed that the length of </em><em>this fish </em><em>ranged between 98 and 211 mm. Ratio of male and female is balance and have negative allometric growth pattern show that the length of growth is more faster than the weight of growth. More than 50% of fish sample both males and females were immature gonads. During observation, length of  first maturity was 196 mm and the average length of captured was 146 mm. </em><em>Many fishes caught was smaller than Lm, It will interfere the sustainability of japanese threadfin bream.</em></p>

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Life History ◽  
Food Web ◽  
Interaction Strength ◽  
Ecosystem Dynamics ◽  
Stream Fishes ◽  
Migratory Fish ◽  
Migratory Species ◽  
Different Types ◽  
Migratory Stream ◽  
Migratory Fishes

<em>Abstract</em>.—Migratory fishes are common in freshwaters throughout the world and can fundamentally alter recipient ecosystems. We describe different types of fish migrations and consider their importance from the perspective of ecosystem subsidies—that is, landscape-scale flows of energy, materials, and organisms that are important in driving local food web and ecosystem dynamics. We distinguish between two general categories of subsidies, which we term here material subsidies and process subsidies. Material subsidies are the transfer of energy, nutrients, and other resources resulting in direct changes in resource pools within ecosystems. We posit that material subsidies occur under only a subset of life history strategies and ecological settings, and the potential for migratory fish to represent major material subsidies is greatest when (1) the biomass of migrants is high relative to recipient ecosystem size, (2) the availability of nutrients and energy is low in the recipient ecosystem (i.e., oligotrophic), and (3) there are effective mechanisms for both liberating nutrients and energy from migratory fishes and retaining those materials within the food web of the recipient ecosystem. Thus, anadromous semelparous Pacific salmon <em>Oncorhynchus </em>spp. with en masse programmed senescence in oligotrophic Pacific Northwest streams can be large material subsidies. In contrast, process subsidies arise from feeding or other activities of migratory species that directly affect process rates within recipient ecosystems. For example, the physical and chemical effects of grazing and sediment-feeding fishes such as prochilodontids, as well as seed dispersal by large-bodied frugivorous characins, represent potentially key process subsidies by migratory fishes in some of the great rivers of South America. We speculate that process subsidies are more widespread than material subsidies from migratory stream fishes because they are independent of the type of migration patterns, life history, and distance traveled. Nevertheless, the magnitude of process subsidies is likely to be greatest under a specific subset of ecological conditions, which can differ from those where material subsidies might be most important. In addition to migrant biomass, the potential for migratory fish to represent strong process subsidies is regulated by migrant interaction strength and the degree to which a migratory species is functionally unique in a particular ecological setting. Unlike material subsidies, which require high migrant biomass as conveyor belts of materials, migratory fishes can be crucial process subsidies, even when migrant biomass is low, if they are functionally unique and strong interactors. We provide specific examples of these different types of subsidies and outline key directions of research for furthering our understanding of the functional significance of migratory stream fishes. Our aim is to highlight the diversity of subsidies provided by migratory fishes in order to foster a more comprehensive perspective on fishes as essential components of riverine ecosystems.

scholarly journals Length-Weight and Length-Length Relationships in Freshwater Garfish Xenentodon cancila (Ham.) from Muriyadhar, Sunsari, Nepal

2015 ◽  
Vol 26 ◽  
pp. 10-14
Author(s):  
Bharat Raj Subba ◽  
Satya Narayan Mehta ◽  
Shaligram Adhikaree
Keyword(s):  
Body Weight ◽  
Fresh Water ◽  
Growth Pattern ◽  
Standard Length ◽  
Allometric Growth ◽  
B Values ◽  
Total Length ◽  
Length Standard ◽  
Length Relationship ◽  
Xenentodon Cancila

Present paper attempts to describe length-weight (LW) and total length-standard length (TL and SL) relationships of fresh-water garfi sh Xenentodon cancila. Fish of different length and weight were caught using cast nets from Muriyadhar, Sunsari. The fish were kept in ice box in fresh condition and brought to fi sh laboratory, Department of Zoolog post Graduate Campus, Biratnagar. The data obtained from measurement were analysed using the formula W = aLb. The b values estimated for the total length and standard length in relation to body weight were 3.2202 and 3.2559 respectively. The values of b clearly indicate the allometric growth pattern and for total length and standard length relationship, the linear value of b was 0.3223.J. Nat. Hist. Mus. Vol. 26, 2012: 10-14

scholarly journals Landscape edges shape dispersal and population structure of a migratory fish

Oecologia ◽  
2019 ◽  
Vol 190 (3) ◽  
pp. 579-588 ◽  
Author(s):  
M. A. Kaemingk ◽  
S. E. Swearer ◽  
S. J. Bury ◽  
J. S. Shima
Keyword(s):  
Population Structure ◽  
Migratory Fish

Genetic population structure and connectivity in a commercially exploited and wide-ranging deepwater shark, the leafscale gulper (Centrophorus squamosus)

2012 ◽  
Vol 63 (6) ◽  
pp. 505 ◽  
Author(s):  
A. Veríssimo ◽  
J. R. McDowell ◽  
J. E. Graves
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
New Zealand ◽  
Indian Ocean ◽  
Genetic Homogeneity ◽  
Genetic Population Structure ◽  
Maturity Stage ◽  
Genetic Population ◽  
The Indian Ocean ◽  
Nuclear Loci

The leafscale gulper (Centrophorus squamosus) is a wide-ranging deepwater benthopelagic shark threatened by commercial fisheries in parts of its range. Despite concerns about resource sustainability, little is known about the population structure and connectivity between critical habitats of the leafscale gulper. This study investigates the genetic population structure and the migration patterns of C. squamosus using nuclear microsatellites and mitochondrial NADH dehydrogenase subunit 2 (ND2) gene sequences. Genetic diversity was estimated and compared among sample collections from off Ireland, Portugal, the Azores, South Africa and New Zealand. The null hypothesis of genetic homogeneity among all collections was not rejected by the nuclear loci (FST (the overall genetic differentiation among sample collections) = –0.002, P = 0.88), but we found long-term genetic divergence between New Zealand and the remaining collections at the mtDNA ND2 (FCT (genetic differentation among groups of sample collections) = 0.366, P = 0.000). Migration rate estimates indicated limited female dispersal across the Indian Ocean whereas males showed less restricted dispersal. Our results are consistent with a single genetic stock of C. squamosus and the existence of sex-biased dispersal across the Indian Ocean. Widespread genetic homogeneity at nuclear loci minimizes the loss of unique adaptive genetic diversity in the event of localised depletion. However, high local fishing mortality may have far reaching impacts given the marked sex- and maturity-stage-based habitat partitioning previously reported for C. squamosus.

Fecundity of the deep-sea fish in the north-east atlantic Alepocephalus bairdii (Pisces: Alepocephalidae)

1999 ◽  
Vol 79 (4) ◽  
pp. 765-767 ◽  
Author(s):  
V. Allain
Keyword(s):  
Standard Length ◽  
Deep Sea ◽  
Batch Fecundity ◽  
East Atlantic ◽  
The West ◽  
Spawning Period ◽  
North East ◽  
The North ◽  
First Maturity ◽  
Sea Fish

Alepocephalus bairdii is a deep sea fish caught but discarded by semi-industrial fisheries from the north-east Atlantic Ocean. Reproductive features were investigated on 448 females of 29–93 cm standard length (SL) captured over 2 y (December 1995–December 1997) at 800–1280 m off the west coast of the British Isles. The first maturity of females was determined at L50=55 cm SL. A well-defined spawning period could not be determined in this species; a batch spawner characterized by an indeterminate annual fecundity. Absolute batch fecundity was estimated between 458 and 7049 oocytes per female 63–88 cm SL.

scholarly journals INITIAL DEVELOPMENT OF CLADODE GIANT SWEET CLONE AS A FUNCTION OF WATER AND SALINE STRESS

2021 ◽  
Vol 39 (2) ◽  
pp. 279-292
Author(s):  
Leandro Ricardo Rodrigues de LUCENA ◽  
Álefe Chagas de Lima COSTA ◽  
Antonio Dennys Melo de OLIVEIRA ◽  
Maurício Luiz de Mello Vieira LEITE
Keyword(s):  
Response Surface ◽  
Surface Analysis ◽  
Experimental Period ◽  
High Energy ◽  
Water Levels ◽  
Response Surface Analysis ◽  
Saline Stress ◽  
Morphometric Characteristics ◽  
Initial Development ◽  
Four Levels

Forage plants are considered one of the main factors for the development of livestock worldwide, for presenting high potential for phytomass production, drought tolerance, high energy value, large water reserve and easy propagation. Forage cactus stands out for its tolerance to water deficit. Aimed to evaluate the initial performance of the morphometric characteristics of Giant Sweet clone (N. cochenillifera) submitted to water and saline stresses using response surface analysis. Design used was completely randomized in a 4x4 factorial scheme, composed of four levels of water replacement, based on crop evapotranspiration (ETc): (25%.ETc, 50%.ETc, 75%.ETc and 100%.ETc) and four levels of water salinity (0, 2, 4 and 8 dS/m), with four repetitions totalling 64 experimental units. The following morphometric characteristics were evaluated: plant height, length, width, thickness, number of cladodes and area of cladodes. Eight evaluations were realized during the experimental period. Response surface analysis was used to evaluate the morphometric characteristics of the cladodes. Best water levels were between 55%.ETc and 65%.ETc and saline levels between 3.5 and 5 dS/m, maximizing the morphometric characteristics of Giant Sweet clone.

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