Reproductive dynamics of broadbill swordfish, Xiphias gladius, in the domestic longline fishery off eastern Australia

2003 ◽  
Vol 54 (4) ◽  
pp. 315 ◽  
Author(s):  
Jock Young ◽  
Anita Drake ◽  
Michael Brickhill ◽  
Jessica Farley ◽  
Thor Carter
Keyword(s):  
New Zealand ◽  
Gonadosomatic Index ◽  
Fork Length ◽  
Reproductive Period ◽  
Fish Length ◽  
Batch Fecundity ◽  
Spawning Period ◽  
Fish Size ◽  
Eastern Australia ◽  
Xiphias Gladius

The reproductive ecology of broadbill swordfish, Xiphias gladius, was evaluated based on 1437 fish (size range 50–300 cm orbital fork length [OFL]) caught in the domestic longline fisheries off eastern Australia and New Zealand between May 1999 and March 2001. Reproductive activity was assessed using histology, a gonadosomatic index, and maximum oocyte size. Males were significantly smaller than females and represented less than one third of the sampled fish. Sex ratio differed significantly with respect to fish size and time of year. Females began maturing at 150-cm OFL and spawned from September to March, with the greatest activity from December to February. Males matured at 90-cm OFL; ripe males were found from January to March, but also in May and October, suggesting an extended reproductive period. During the spawning period the proportion of spawning to inactive mature sized females was significantly higher in waters west of longitude 158°E than in waters to the east. Further to the east, samples taken from the New Zealand fishery showed no actively spawning fish during the main spawning period. Females were increasingly reproductively active as water temperature increased beyond 24°C and sea surface chlorophyll a decreased below 0.2 μg L–1. Batch fecundity was linearly related to fish length with a mean batch fecundity of 1.66 million oocytes for females ranging in size from 173- to 232-cm OFL. The presence of hydrated oocytes and post-ovulatory follicles (POFs) in the same ovaries indicated multiple spawnings. Depending on the time taken for POFs to degrade, these may have been daily at the height of the spawning season.

Reproductive characteristics and per-recruit analyses of blue warehou (Seriolella brama): implications for the South East Fishery of Australia

2001 ◽  
Vol 52 (4) ◽  
pp. 575 ◽  
Author(s):  
Ian A. Knuckey ◽  
K. P. Sivakumaran
Keyword(s):  
Egg Production ◽  
East Coast ◽  
Gonadosomatic Index ◽  
Fork Length ◽  
Size At Maturity ◽  
Current Management ◽  
Spawning Period ◽  
Gill Net ◽  
Trawl Fishing

Monthly samples of commercial catches of S. brama were collected between May 1996 and December 1997 in three regions of the fishery:off the east coast of Victoria; eastern Tasmania; and western Bass Strait. Sex ratio, gonadosomatic index, macroscopic and histological development, size at maturity and fecundity were estimated and combined with data on growth and mortality to perform per-recruit analyses. The main spawning period was during winter–spring and there was evidence of spawning in each of the three regions. Blue warehou reach maturity at 30–40 cm fork length. They have a determinate annual fecundity and spawn around three batches of eggs during a season. Eggs-per-recruit analyses revealed maximum egg production at ~40 cm (4–5 years) in an unfished population. Gill-net fishing, which targets fish >45 cm, was less likely to affect the relative eggs-per-recruit in a population than trawl fishing, which catches a wider range of smaller fish. These results are discussed in light of the current management arrangements in the fishery and will be used in models to assess the effect of fishing on the long-term sustainability of the blue warehou.

scholarly journals Fishery, diet composition and reproductive biology of the dolphinfish Coryphaena hippurus (Linnaeus, 1758) off Karnataka, south-west coast of India

2016 ◽  
Vol 63 (4) ◽  
Author(s):  
K. M. Rajesh ◽  
Prathibha Rohit ◽  
E. M. Abdussamad
Keyword(s):  
Reproductive Biology ◽  
Diet Composition ◽  
Gradual Increase ◽  
Gonadosomatic Index ◽  
Fork Length ◽  
Spawning Period ◽  
Coryphaena Hippurus ◽  
South West ◽  
South West Coast ◽  
Index Of Relative Importance

Fishery, diet composition and reproductive biology of the dolphinfish Coryphaena hippurus (Linnaeus, 1758) landed along Karnataka Coast during 2013-15 were studied. The estimated average landing of the species in India during the study period was 7975 t of which Karnataka contributed 2.73% (218 t). The fish is mainly exploited by gillnet and also by troll lines operated from trawlers. A few stray specimens were also landed by purse seines. The fork length (FL) was in the range of 32-128 cm and fishes in the length range (FL) of 55-90 cm dominated the catch, contributing 79.8% of the total landings. The most dominant prey item, in terms of occurrence (70.57%) and weight (83.18%) were finfishes followed by cephalopods (19.62% by occurrence and 13.66% by weight) and crustaceans (7.01% occurrence and 1.32% by weight). The index of relative importance (IRI ) values were 85.3, 13.39 and 0.68% respectively for fish, cephalopods and crustaceans respectively. Sex ratio (1:2.05) indicated dominance of females in the fishery. Presence of mature and spent specimens throughout the year suggests that the species spawns all through the year. Peak spawning period was from June to September. This coincided with gradual increase in gonadosomatic index (GSI) values ahead of May which reached a peak during August-September.

scholarly journals Reproductive Ecology ofProchilodus brevisan Endemic Fish from the Semiarid Region of Brazil

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Liliane de Lima Gurgel ◽  
José Roberto Verani ◽  
Sathyabama Chellappa
Keyword(s):  
Gonadosomatic Index ◽  
Reproductive Ecology ◽  
Temporal Distribution ◽  
Gonadal Development ◽  
Neotropical Region ◽  
Reproductive Period ◽  
Semiarid Region ◽  
Spawning Period ◽  
Gonadal Maturity ◽  
Commercially Important

The commercially important migratory fishProchilodus brevisis from the Neotropical region, and understanding the reproductive ecology of this potamodromous fish is essential for its conservation and management. This study investigated the length-mass relationship, sex ratio, length at first gonadal maturity, gonadal development stages, gonadosomatic index, condition factor, and reproductive period ofP. brevis. Temporal distribution of rainfall, temperature, dissolved oxygen concentration, pH, and electrical conductivity of the water were related to the reproductive period of this fish. Rainfall seems to be the main environmental factor which modulates changes in limnological parameters and the timing of the spawning period of this fish.P. brevismigrates into lower reaches of the river to feed during the dry season and returns to the upper reaches during the rainy season to spawn. Inadequate facilities for migration create obstacles for spawning success of this ecologically important fish.

Age, growth and reproduction of the golden grey mullet, Chelon auratus (Risso, 1810) in the Golden Horn Estuary, Istanbul

2020 ◽  
Vol 100 (6) ◽  
pp. 989-995
Author(s):  
Mert Kesiktaş ◽  
Emre Yemişken ◽  
Taner Yildiz ◽  
Lütfiye Eryilmaz
Keyword(s):  
Gonadosomatic Index ◽  
Fish Length ◽  
Growth Equation ◽  
Grey Mullet ◽  
Spawning Period ◽  
Pooled Data ◽  
Golden Horn ◽  
Reproduction Biology ◽  
Von Bertalanffy Growth Equation ◽  
Growth And Reproduction

AbstractAge, growth and reproduction biology of the golden grey mullet, Chelon auratus (Risso, 1810) have been studied in the Istanbul Golden Horn area. Fish length ranged from 13.4–46.8 cm, and age from 1–10 years, respectively. The sex ratio (female:male) was 1:1.08. The length-weight relationship was estimated as W = 0.0127L2.89, W = 0.0099L2.97 and W = 0.0156L2.82 for both sexes combined, females and males, respectively. The von Bertalanffy growth equation parameters were: L∞ = 57.52 cm, K = 0.1 year−1, t0 = −2.24 year for pooled data. The gonadosomatic index (GSI) values indicated the major spawning period was between August and November, and the minor spawning peak between March and April. The highest GSI values were observed in September. The length and age of sexual maturity were estimated as 26.2 cm and 4 years for males and 24.1 cm and 3 years for females.

Reproductive biology of blue mackerel, Scomber australasicus, off southern and eastern Australia: suitability of the Daily Egg Production Method for stock assessment

2009 ◽  
Vol 60 (2) ◽  
pp. 187 ◽  
Author(s):  
P. J. Rogers ◽  
T. M. Ward ◽  
L. J. McLeay ◽  
M. Lowry ◽  
R. J. Saunders ◽  
...  
Keyword(s):  
Reproductive Biology ◽  
Egg Production ◽  
Stock Assessment ◽  
Fork Length ◽  
Production Method ◽  
Spawning Season ◽  
Batch Size ◽  
Batch Fecundity ◽  
Eastern Australia ◽  
Mature Fish

The present study investigated the reproductive biology of blue mackerel (Scomber australasicus) off southern and eastern Australia and assessed the suitability of the Daily Egg Production Method (DEPM) for future stock assessment. This analysis revealed that S. australasicus is a serial spawner with asynchronous oocyte development and indeterminate fecundity. S. australasicus spawns between November and April off southern Australia and between July and October off eastern Australia. In southern Australia, ~50% of males and females were mature at 236.5 and 286.8 mm fork length (FL), respectively. Size at ~50% maturity could not be estimated reliably for eastern Australia owing to the smaller proportion of mature fish in samples. Mean spawning frequencies ranged from 2 to 11 days off southern Australia. Batch fecundity was related to fish size and mean batch size was 69 894 ± 4361 oocytes per batch and 134 oocytes per g of weight. The timing and duration of the spawning season, size at maturity, spawning frequency and batch fecundity of S. australasicus off southern Australia were consistent with those of S. japonicus in the northern Pacific Ocean. The present study’s estimates of adult reproductive parameters of S. australasicus off southern Australia were suitable for the application of the DEPM for estimating spawning biomass. Collecting representative samples of mature fish from waters off eastern Australia during the spawning season is a high priority for future stock assessment of this species.

A multifaceted approach to modelling growth of the Australian bonito, Sarda australis (Family Scombridae), with some observations on its reproductive biology

2013 ◽  
Vol 64 (7) ◽  
pp. 671 ◽  
Author(s):  
J. Stewart ◽  
W. D. Robbins ◽  
K. Rowling ◽  
A. Hegarty ◽  
A. Gould
Keyword(s):  
Fork Length ◽  
Maximum Growth ◽  
Austral Spring ◽  
Spawning Period ◽  
Growth Functions ◽  
Eastern Australia ◽  
Rate Maximum ◽  
Males And Females ◽  
Using Data ◽  
Size At Age

Growth of the Australian bonito, Sarda australis, is described for the first time using data from three different sources. Von Bertalanffy growth functions were fitted to: (1) size-at-age data derived from sectioned sagittal otoliths, (2) monthly length–frequency collections from a commercial line fishery, and (3) tag–recapture data from a long-term cooperative tagging study. Age estimates of S. australis were indirectly validated by examining the percentage of otoliths with opaque edges each month. The best-fitting growth functions for each data source yielded similar results, showing strong seasonal variations in growth rate. Maximum growth occurred during summer, with near cessation of growth apparent during winter. Early growth was very fast, with fish attaining ~30 cm fork length (FL) after 3–4 months. Growth of males and females was not significantly different. The oldest fish sampled was estimated to be 3+ years old, while the largest fish aged was 63.8 cm FL. Gonadosomatic indices indicated that S. australis has an austral spring/summer spawning period in eastern Australia. A preliminary estimate of the size at first sexual maturity was ~36 cm FL for both males and females, corresponding to an age of ~1 year.

scholarly journals Seasonal analysis of condition, biochemical and bioenergetic indices of females of Brazilian flathead, Percophis brasiliensis

2013 ◽  
Vol 11 (1) ◽  
pp. 153-162 ◽  
Author(s):  
Karina A. Rodrigues ◽  
Gustavo J. Macchi ◽  
Agueda Massa ◽  
María I. Militelli
Keyword(s):  
Energy Density ◽  
Reproductive Cycle ◽  
Biochemical Composition ◽  
Seasonal Pattern ◽  
Gonadosomatic Index ◽  
Energy Allocation ◽  
Reproductive Period ◽  
Spawning Period ◽  
Different Tissues ◽  
Percophis Brasiliensis

Percophis brasiliensis is a demersal species that constitutes an important resource of Argentine coastal fisheries. Nevertheless, information about bioenergetic dynamic of reproduction has not been reported. Therefore, seasonal variations of condition factors, biochemical composition and energy density of different tissues were analyzed in order to determine the strategy of energy allocation during the reproductive cycle of this species. Condition indices (hepatosomatic and K) showed a seasonal pattern opposite to that observed for gonadosomatic index, which was characterized by higher values during the reproductive period (spring-summer), decreasing at the end of spawning. Biochemical composition of different tissues also showed a clearly seasonality associated to reproductive cycle. Analysis of energy density variation of liver indicates that P. brasiliensis accumulate reserves in winter before reproduction, which later decrease during the spawning season. In contrast, the energy density in muscle did not show significant differences among seasons, indicating that individuals could be also using an external source of energy during spawning. Therefore, it is possible that P. brasiliensis respond to an intermediate strategy of energy allocation, combining characteristics of both capital breeders (stores energy previous to the onset of reproductive activity) and income breeders (acquire energy by active feeding during spawning period).

scholarly journals REPRODUCTIVE BIOLOGY OF THE MULLET LIZA FALCIPINNIS (VALENCIENNES, 1836) IN TWO AFRICAN COMPLEXS LAGOONS (EBRIÉ AND GRAND-LAHOU) (CÔTE D’IVOIRE)

2018 ◽  
Vol 6 (5) ◽  
pp. 114-127
Author(s):  
Ebram Luc Gervais ◽  
Soumaïla SYLLA ◽  
Tizié Thierry ZAN-BI ◽  
Boua Célestin ATSE
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Fork Length ◽  
Total Body Weight ◽  
Hepatosomatic Index ◽  
Spawning Period ◽  
Total Body ◽  
Monthly Variations

The reproduction of Liza falcipinnis were investigated in both lagoons (Ebrié and Grand-Lahou) from January 2006 to december 2007. 2162 specimens were examined (914 and 1248 respectively in Ebrié and Grand-Lahou lagoons). Fork length was taken to the nearest 1 mm, and total body weight (TW) and eviscerated body weight (EW) to the nearest 0.1 g. The gonads and the liver were then established removed, weighted to the nearest 0.001g. The reproduced period of Liza falcipinnis was established by analysing the temporal evolution of the frequency of the maturity stages and the monthly variations in the gonadosomatic index (GSI), the hepatosomatic index (HIS) and the condition factor (K). Sex ratio was established taking into account the sex determinations. The size at which 50 % of the specimens became mature (FL50) was estimated. The sex ratio (1:1.24) and (1:1.40) observed respectively in Ebrié and Grand-Lahou lagoons were in favour of females. The first sexual maturity size was 21.0 cm (FL) for males and 27.9 cm (FL) for females in Ebrié lagoon and 24.7 cm (FL) for males and 27.9 cm (FL) for females in Grand-Lahou lagoon. Liza falcipinnis spawns in lagoon and the spawning period ranged from December to April.

scholarly journals Gonadal development and reproductive period of the characin Astyanax aff. bimaculatus (Characiformes: Characidae) in a tropical reservoir in southeastern Brazil

2019 ◽  
Vol 36 ◽  
pp. 1-14
Author(s):  
Francisco G. Araújo ◽  
Aparecida A. Nascimento ◽  
Iracema D. Gomes ◽  
Armando Sales ◽  
Beatriz A. Chagas de Oliveira
Keyword(s):  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Neotropical Region ◽  
Reproductive Period ◽  
Southeastern Brazil ◽  
Energy Reserves ◽  
Tropical Reservoir ◽  
Spawning Period ◽  
Wide Range ◽  
Body Energy

The gonadal development of the characin Astyanax aff. bimaculatus from Funil Reservoir, an impoundment in the middle reaches of the Paraiba do Sul River in southeastern Brazil was analysed through histological, histochemical and histometric techniques, and the spawning season was determined. Unbalanced sex ratio was found, with females outnumbering and reaching larger sizes than males. The following stages of oogenic cell development were identified for females: primary growth, pre-vitellogenic (cortical alveolar) and vitellogenic. In males, the following stages were determined: spermatogonia primary and secondary, spermatocyte primary and secondary, spermatid and spermatozoa. The spawning occurs most of the year, peaking in January-February, as indicated by the gonadosomatic index. In the peak of the spawning period, the condition factor and hepatosomatic indices decreased suggesting use of stored body energy reserves during the reproduction. Spawning in batches, small-sized oocytes and a long reproductive season suggest that Astyanax aff. bimaculatus fits to an opportunist strategy. Such strategy may facilitate the use of a wide range of lentic and lotic body waters in the Neotropical region.

Melampsora medusae. [Descriptions of Fungi and Bacteria].

1975 ◽  
Author(s):  
J. Walker
Keyword(s):  
New Zealand ◽  
Geographical Distribution ◽  
Northern Hemisphere ◽  
Populus Deltoides ◽  
Leaf Damage ◽  
Main Method ◽  
Melampsora Medusae ◽  
Nursery Stock ◽  
Eastern Australia ◽  
Incremental Growth

Abstract A description is provided for Melampsora medusae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Pycnia and aecia on Coniferae, especially Larix and Pseudotsuga, less commonly on Pinus and other genera (Ziller, 1965). Uredinia and telia on species of Populus, especially Populus deltoides, and its varieties and hybrids P. balsamifera, P. nigra var. italica and others. Its exact host range on species of Populus is not known due to confusion with other species of Melampsora and to uncertainty in the reported identity of some species of Populus and clones (Walker, Hartigan & Bertus, 1974). DISEASE: Leaf rust of poplars, causing severe leaf damage and early defoliation on susceptible species and clones. Continued defoliation of successive flushes of growth predisposes trees to winter injury and dieback (Peace, 1962) and can cause death of trees, especially nursery stock and trees 1-2 yr old (25, 204; 47, 241; Walker Haitigan & Bertus, 1974). Reduction in incremental growth of timber occurs with susceptible varieties. Some damage can occur to the conifer hosts. It is often severe on Pseudotsuga menziesii (45, 459; 47, 126) and in nurseries Pinus spp. and Larix spp. can be heavily attacked (Ziller, 1965). GEOGRAPHICAL DISTRIBUTION: North America (Canada, USA), Asia (Japan); Australasia and Oceania (Australia, New Zealand); Europe (France, Spain). Reports of Melampsora spp. on poplars (including P. deltoides and P. canadensis) from South America (Argentina, 21, 173), Uruguay (Lindquist & de Rosengurtt, 1967) may refer in part to M. medusae. TRANSMISSION: By air-borne urediniospores, often over long distances (suspected from eastern Australia to New Zealand). Urediniospores survive the winter in milder climates on semi-evergreen lines and on green sucker growth of deciduous trees. This is probably the main method of overwintering in the Southern Hemisphere and in warmer parts of the Northern Hemisphere. The possibility of bud carryover as occurs with M. epitea on Salix in Iceland (Jorstad, 1951) and the Canadian Arctic (Savile, 1972) should be investigated. Telia survive the winter and basidiospores formed in spring infect susceptible conifers in parts of the Northern Hemisphere (Ziller, 1965) but no conifer infection has so far been found in Australia.

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