scholarly journals The most important fishery resource in the Amazon, the migratory catfish Brachyplatystoma vaillantii (Siluriformes: Pimelodidae), is composed by an unique and genetically diverse population in the Solimões-Amazonas River System

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Kyara Martins Formiga ◽  
Jacqueline da Silva Batista ◽  
José Antônio Alves-Gomes
Keyword(s):  
Life Cycle ◽  
River System ◽  
Main Channel ◽  
Diverse Population ◽  
Single Population ◽  
Migration Patterns ◽  
Fishery Resource ◽  
Mitochondrial Dna Control Region ◽  
Molecular Variance ◽  
Management And Conservation

ABSTRACT The migratory catfish Brachyplatystoma vaillantii is one of the most important fishery resources in the Amazon. Intense capture occurs associated to its life cycle. In order to know the genetic status, we sequenced the mitochondrial DNA control region from 150 individuals of B. vaillantii, collected in five fishing landing locations, covering the length of the Solimões-Amazonas River in Brazil. Genetic diversity parameters suggest there is no genetic differentiation between the five localities. Population’s expansion indicated by R 2 and Fu’s Fs tests was also confirmed by the high number of unique haplotypes found. The Analyses of molecular variance indicated that nearly all variability was contained within locations (99.86%), and estimates of gene flow among B. vaillantii were high (F ST = 0.0014). These results suggest that Brachyplatystoma vaillantii forms a panmitic population along the Solimões-Amazonas River and, has greater genetic variability than other species of the Brachyplatystoma genus available so far. Although the influence of different tributaries on B. vaillantii migration patterns remains uncertain, a single population in the main channel should be consider in future policies for management of this resource. However, since the species’ life cycle uses habitats in several countries, its management and conservation depend greatly of internationally joined efforts.

scholarly journals Hard times for catadromous fish: the case of the European eel (Anguilla anguilla, L. 1758)

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Cinzia Podda ◽  
Andrea Sabatini ◽  
Francesco Palmas ◽  
Antonio Pusceddu
Keyword(s):  
Life Cycle ◽  
Anguilla Anguilla ◽  
Cultural Value ◽  
European Eel ◽  
Migration Patterns ◽  
Habitat Occupancy ◽  
Hard Times ◽  
Ancient Times ◽  
And Migration ◽  
Anthropogenic Threats

Catadromous fish species are very important organisms for their ecological, economical, and cultural value. For its complex life species catadromous fish result in worldwide decline since the beginning of the 20th century. Among the most iconic catadromous species, the European eel Anguilla anguilla L. 1758 has aroused considerable interest since very ancient times. Because, to date, many aspects of their life cycle remain relatively unknown, to implement our knowledge about the main natural and anthropogenic threats to its survivorship and identify possible solutions to preserve it, in this narrative review, we present the state of the knowledge about the life cycle, habitat occupancy, recruitment, and migration patterns of the European eel and about the major threats most likely have contributed to the decline of eels’ populations.

scholarly journals Length-weight relationships of the Indian Major Carp, Labeo rohita (Cypriniformes: Cyprinidae) from six drainages of Ganga basin, India

2015 ◽  
Vol 7 (1) ◽  
pp. 71-77
Author(s):  
Javaid Iqbal Mir ◽  
Uttam Kumar Sarkar ◽  
Om Prakash Gusain ◽  
Arvind Kumar Dwivedi
Keyword(s):  
Labeo Rohita ◽  
Main Channel ◽  
Coefficient Of Determination ◽  
Important Food ◽  
Indian Major Carp ◽  
Ganga Basin ◽  
Natural Range ◽  
Food Fish ◽  
Management And Conservation ◽  
Tropical Freshwater

The Indian Major Carp, Labeo rohita, is a geographically widespread and economically important food fish species in tropical freshwater of India and adjacent countries. We studied the lengthweightrelationships of 1 033 specimens collected from the main channel of Ganga river and its five major drainages from March 2009 to July 2012. The length of males ranged from 16 to 92cm (females: 16to 94cm). The growth is allometric positive (b>3) for males, females and pooled sexes. The coefficient of determination (r2) in males ranged from 0,978 to 0,989 and for females from 0,958 to 0,985. Data from field populations are scarce and our results will be useful in the management and conservation of L. rohita populations in its natural range.

scholarly journals Reproductive Phenology and Size Structure Characteristics of Hypseleotris agilis (Herre, 1927) in Lake Mainit, Philippines

2020 ◽  
Vol 80 ◽  
pp. 35-42
Author(s):  
Joycelyn C. Jumawan ◽  
Paula Marie Hidalgo ◽  
Romell A. Seronay
Keyword(s):  
Native Species ◽  
Condition Factor ◽  
Size Structure ◽  
Gonadosomatic Index ◽  
Reproductive Phenology ◽  
Hepatosomatic Index ◽  
Fishery Resource ◽  
Gravid Females ◽  
Management And Conservation

Hypseleotris agilis locally known as Bugwan is a native species and one of the most abundant fishes of commercial value in Lake Mainit, Philippines. A total of 1,584 H. agilis from Lake Mainit near the mouth of Kalinawan and Puyo River were caught from May 2018 to February 2019 to determine the length-weight relationship (LWR), condition factor (K), gonadosomatic index (GSI) and hepatosomatic index (HSI) of this species. Positive allometric growth was observed for both sexes (b>3). Sex ratio indicated the dominance of males over females as much as 58.7%. The number of ripe males and gravid females was observed throughout the months of the collection, which indicates the ability of the fish species to spawn continuously throughout the year. Determination of GSI in both sexes showed higher values during November (males) and December (females). However, HSI values were relatively low during the spawning season, which would indicate the usage of energy for gonadal maturation. The K factor showed high values during the peak spawning months, directly proportional to GSI values. This study provides updated information for management and conservation of this important fishery resource in Lake Mainit.

Migration patterns and estuarine aggregations of a catadromous fish, Australian bass (Percalates novemaculeata) in a regulated river system

2017 ◽  
Vol 68 (8) ◽  
pp. 1544 ◽  
Author(s):  
D. J. Harding ◽  
R. G. Dwyer ◽  
T. M. Mullins ◽  
M. J. Kennard ◽  
R. D. Pillans ◽  
...  
Keyword(s):  
Fish Species ◽  
Large Scale ◽  
River System ◽  
Regulated River ◽  
Regulated Rivers ◽  
Migration Patterns ◽  
Migratory Response ◽  
Resource Managers ◽  
Receiver Array ◽  
Downstream Movement

Catadromous fish species require adequate flows to migrate between fresh and saltwater habitats to reproduce. However, artificial barriers and flow alteration affect fish populations by reducing habitat connectivity and disrupting movement cues. In regulated rivers, it is critical that migratory flow requirements are quantified to optimise water allocation for multiple users. In the present study, we assessed the migratory timing, flow and estuarine aggregation requirements for Australian bass (Percalates novemaculeata). Over 2 years, 66 bass were tracked using an acoustic receiver array in the Logan River (Qld, Australia). Bass performed large-scale downstream movements in response to elevated winter flows (40 and 108m3 s–1), which facilitated migration to the lower estuary, where salinity conditions were appropriate for spawning. Bass migrations occurred only when gonads were mature, despite large flows providing opportunities for movement outside this period. Experimental flow releases from an impoundment (2.1m3 s–1) during winter did not elicit a migratory response. Connectivity between upstream and estuarine habitats was reduced by the presence of instream weirs, with downstream movement across weirs occurring only when sufficient flow magnitude was achieved (>76.1m3 s–1). These findings are relevant for water resource managers formulating environmental flow rules for catadromous fish species in systems with multiple instream artificial barriers.

Preliminary Studies on the Visible Migrations of Adult Salmon

1962 ◽  
Vol 19 (1) ◽  
pp. 137-148 ◽  
Author(s):  
D. V. Ellis
Keyword(s):  
Industrial Development ◽  
River System ◽  
Diurnal Rhythms ◽  
Migration Patterns ◽  
Migratory Season ◽  
Nocturnal Migration ◽  
Field Behaviour

Techniques have been developed for observing and recording the behaviour of migrating adult salmon. Daytime movement through slow water (less than 5 ft/sec (1.5 m/sec)) is by steady swimming in schools. Such steady swimming is interrupted with resting periods at velocities between 3 and 5 ft/sec (1.0–1.5 m/sec) but can be sustained over long periods at velocities less than 3 ft/sec (1 m/sec). Movement through slow water in the Somass River system normally occurs along the line of the deepest channel, wherever this is well defined. Movement through rapids (velocities more than 5 ft/sec or 1.5 m/sec) is by darting interspersed with holding, salmon moving individually rather than in schools. Migration through pools, and through other obstructions such as fishways shows diurnal rhythms, modifications of which are associated with numbers of salmon moving, the time within the migratory season, and the species concerned. Nocturnal migration occurs.Entry of salmon into rivers during the migratory season occurs at intervals, the initiating stimulus for which is frequently related to the passage of atmospheric warm fronts over the river estuary.Techniques for field behaviour studies of salmon migration have a potential for management in that it is possible to undertake such studies in areas scheduled for industrial development and to utilize the revealed spatial and temporal migration patterns in the design of fish diversion facilities.

Migration patterns of five fish species in the Murray-Darling River system

1983 ◽  
Vol 34 (6) ◽  
pp. 857 ◽  
Author(s):  
LF Reynolds
Keyword(s):  
South Australia ◽  
River System ◽  
Migration Patterns ◽  
Demersal Eggs ◽  
Common Carp Cyprinus Carpio ◽  
Reproduction Strategy ◽  
Murray River ◽  
Fish Tagging ◽  
Mature Fish ◽  
Murray Cod

Results of a fish tagging study carried out in the Murray River, South Australia from 1974 to 1978, are presented. Of 14 333 fish tagged, 1276 were recaptured and the records of these recaptures yield evidence on the movements of several species of both commercial and recreational interest. Some golden perch (Macquaria ambigua) migrated extensively upstream, many moving more than 1000 km. The migration followed, and appeared to be triggered by, a rise in water level at the onset of major flooding. The upstream migrations, made only by mature fish, appear to be a reproduction strategy to ensure that the eggs, which are buoyant, are distributed downstream. In contrast, common carp (Cyprinus carpio), which lay adhesive, demersal eggs, did not migrate but made only random, short- distance movements. Although data on other species were fewer due to their smaller populations, it appears that Murray cod (Maccullochella peeli) and catfish (Tandanus tandanus), both of which have demersal eggs, show similar movement patterns to carp whereas silver perch (Bidyanus bidyanus), which lays buoyant eggs, is similar to golden perch. The implications of these results, with regard to the establishment and maintenance of populations of each of the species, are discussed.

Salinization of southwestern Western Australian rivers and the implications for the inland fish fauna - the Blackwood River, a case study

2003 ◽  
Vol 9 (3) ◽  
pp. 161 ◽  
Author(s):  
David L. Morgan ◽  
Dean C. Thorburn ◽  
Howard S. Gill
Keyword(s):  
Western Australia ◽  
Fish Fauna ◽  
River System ◽  
Main Channel ◽  
Gambusia Holbrooki ◽  
River Catchment ◽  
Low Salinity ◽  
Western Australian ◽  
Freshwater Teleosts

Increasing salinities throughout southwestern Western Australia, facilitated by extensive land clearing, have compromised the region's highly endemic freshwater fishes. Salinization of the Blackwood River has resulted in the main channel and upper cleared catchment being dominated by estuarine and halotolerant teleosts. The non-halotolerant species are restricted to the forested non-saline tributaries of the lower catchment. Of the 12 943 fish (13 species) captured in 113 sites, the halotolerant introduced Mosquitofish Gambusia holbrooki was widespread and the most abundant, representing almost 52% of fish caught. The estuarine Western Hardyhead Leptatherina wallacei, which was also widespread throughout the main channel and upper catchment, was the next most abundant, representing ca. 24% of fish caught. Freshwater endemics represented ca. 23% of captures, with the Western Minnow Galaxias occidentalis and Western Pygmy Perch Edelia vittata accounting for most (i.e., ca. 20%). There were significant differences in teleost communities among the naturally vegetated, low salinity tributaries of the river compared with the main channel and upper cleared catchment. While the forested tributaries still contain populations of E. vittata, Nightfish Bostockia porosa and Mud Minnow Galaxiella munda, the elevated salinities in the upper reaches of the Blackwood River system appear to have caused a massive decline in, or extinction of, populations of these species. The protection of the region's unique freshwater teleosts relies on the preservation of their remaining habitat in both the uncleared catchments of the region and in the low salinity forested tributaries within largely cleared systems, such as those in the Blackwood River catchment.

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