scholarly journals Reproductive Traits and Somatic Growth of Diplodus sargus sargus (Linnaeus, 1758) in the Central Algerian Coast (Southern Mediterranean Sea)

2021 ◽  
Vol 21 (08) ◽  
pp. 381-399
Author(s):  
Bilal Boufekane ◽  
Nadia Chakroun-Marzouk ◽  
Elyes Kelai ◽  
Zakia Alioua ◽  
Soumia Amira ◽  
...  
Keyword(s):  
Maximum Yield ◽  
Reproductive Potential ◽  
Somatic Growth ◽  
Reproductive Traits ◽  
Minimum Size ◽  
Diplodus Sargus ◽  
First Results ◽  
Southern Mediterranean ◽  
Protandrous Hermaphrodite ◽  
Algerian Coast

This work provides useful knowledge on the reproductive traits and somatic growth of the white seabream (Diplodus sargus sargus Linnaeus, 1758) of the central sector of the Algerian coast. It aimed to estimate the maximum yield size of this sparid and evaluate its reproductive potential, by presenting the first results on its global fecundity. A total of 497 specimens, ranging in size from 12.4 to 40.3 cm, were monthly and randomly sampled from the artisanal fishery fleet, between January and December 2017. The obtained length-weight relationships indicated negative allometry for males (TW=0.024 TL2.842) and isometry for females (TW=0.016 TL3.013). The white seabream is a digynic protandrous hermaphrodite species. Sex reversal was observed with a large size overlap of 12 to 32 cm with a median of 23.5 cm. The reproductive season was observed from January to May and spawning occurred in spring. The size at first sexual maturity (TL50) was 20.55 cm for both sexes. Based on these results, the current legal minimum size of capture should be raised in the study area.

The Status of the School Shark Fishery in South-Eastern Australian Waters

1959 ◽  
Vol 10 (2) ◽  
pp. 150 ◽  
Author(s):  
AM Olsen
Keyword(s):  
Maximum Yield ◽  
Reproductive Potential ◽  
South Australia ◽  
Slow Growth Rate ◽  
South Eastern ◽  
Pregnant Females ◽  
The Status ◽  
History Of ◽  
Annual Total ◽  
The Mean

The maximum yield of the school shark fishery in south-eastern Australian waters was 4.09 million lb in 1949. The catch has fluctuated since then about a declining trend to 3.18 million lb in 1956. In 1944, 7.3 hooks were required to catch a shark of mean weight 14.7 lb. In 1956 the number of hooks required was almost doubled: 13.6 hooks were needed to catch sharks of mean weight 13.7 lb; the catch per hook dropped from 2.01 to 0.99 lb. Whereas the catch per boat-month remained relatively stable at 4765 lb for 1944 and 4643 for 1956, the number of hooks used per boat-month increased from 2366 to 4668 hooks in 12 years. Throughout this period the mean weight of sharks in eastern Bass Strait remained fairly steady (11-13 lb) whereas there was a drop of 3 lb from a mean weight of 17-20 lb in the predominantly mature portion of the stock in western Bass Strait. Fishermen in South Australia have reported a comparable drop in the mean weight of sharks in their catches. During the period 1941-46 there was unrestricted inshore fishing of juveniles and pregnant females with a consequent severe drop in the inshore population. The subsequent decline in the annual total catch is believed to be due not only to a too intensive offshore fishery but also to the resultant reduced recruitment and depressed reproductive potential caused by the earlier destruction of juveniles and pregnant females. In the data presented in this paper there is evidence that the school shark fishery, which is operating on a single stock of sharks with a slow growth rate, a late sexual maturity, and a low fecundity, shows trends which are suggestive of depletion. Because similar trends in the soupfin shark fishery of California and in the dogfish fishery of British Columbia were followed by depletion, it has been inferred that regulations to protect the vulnerable phases of the life history of the school shark of Australia may be required. Measures for conservation are discussed.

Ovigeny strategy of the parasitic wasp Cosmocomoidea annulicornis (Hymenoptera: Mymaridae): effect of female age, feeding and host availability on reproductive traits

2021 ◽  
pp. 1-8
Author(s):  
Carolina Manzano ◽  
Eduardo G. Virla ◽  
Maria V. Coll Araoz ◽  
Erica Luft-Albarracin
Keyword(s):  
Body Size ◽  
Parasitic Wasp ◽  
Reproductive Potential ◽  
Reproductive Traits ◽  
Egg Load ◽  
Biological Traits ◽  
Potential Fecundity ◽  
Female Age ◽  
Host Availability ◽  
Egg Maturation

Abstract The reproductive traits of the mymarid wasp Cosmocomoidea annulicornis (Ogloblin) (Hymenoptera: Mymaridae) attacking eggs of the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae) were evaluated under laboratory conditions. Bioassays were carried out to estimate the realized fecundity and egg load of females. The ovigeny index was calculated and different biological traits, such as body size, oöcyte length, gaster length and wing length, were analysed to assess significant associations between these traits and the species fitness. In addition, the effect of host availability and feeding on longevity and potential fecundity throughout life and the effect of female age on egg maturation dynamics were assessed. The results showed that C. annulicornis is a strongly synovigenic species. A positive correlation was found between fecundity and longevity of the females and between body size and oöcyte length. Contrary to expected, body size was not related to fecundity and longevity. Females lived significantly longer in the presence of hosts and honey than when they were host-deprived and honey-fed or both host and honey deprived. Host availability had a significant effect on the amount of eggs laid by C. annulicornis females. Female age was negatively associated with oöcyte length. Furthermore, females were able to mature additional eggs as they aged, nevertheless, when host-deprived, senescent females presented significantly less mature eggs than younger ones, suggesting a possible egg oosorption. These results might contribute to a better understanding of the reproductive potential of this species as a biocontrol agent.

Spawning Mode and Reproductive Output of the Tropical Cephalopod Idiosepius pygmaeus

1993 ◽  
Vol 50 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Andrew R. Lewis ◽  
J. Howard Choat
Keyword(s):  
Body Weight ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Potential ◽  
Adult Life ◽  
Somatic Growth ◽  
Egg Laying ◽  
Adult Life Span ◽  
Adult Weight ◽  
Food Stress

Reproductive biology of the tropical sepioid cephalopod Idiosepius pygmaeus was investigated in wild specimens and in individuals maintained in aquaria through the adult life span. This species produced multiple egg batches over 80% of the observable adult weight range, indicating a coordination of reproductive and somatic growth. Reproductive output was consistent within, but variable between, individuals. Oocyte synthesis and maturation occur continuously after sexual maturation has been reached. Senescence and death are not related to an exhaustion of reproductive potential. On average, captive female I. pygmaeus with access to unlimited food produced 640 eggs in 11 batches over 18 d. When reproductive output was expressed as a ratio of dry female body weight, on average, specimens had incorporated five times their body weight into eggs and egg coatings. Under food stress, captive specimens laid fewer eggs but maintained egg size and periodicity of egg laying. Food stress had no effect on either laying duration or weight at death. This study provides further evidence that terminal spawning modes are not ubiquitous amongst cephalopods.

Reproductive traits and seasonal variability ofMerluccius merlucciusfrom the Tunisian coast

2014 ◽  
Vol 94 (7) ◽  
pp. 1545-1556 ◽  
Author(s):  
Widien Khoufi ◽  
Rosalia Ferreri ◽  
Héla Jaziri ◽  
Safouène El Fehri ◽  
Antonella Gargano ◽  
...  
Keyword(s):  
Seasonal Variability ◽  
Fishery Management ◽  
Somatic Growth ◽  
Reproductive Traits ◽  
North African ◽  
Spawning Period ◽  
Tunisian Coast ◽  
The North ◽  
Significant Relationships ◽  
First Maturity

Merluccius merlucciusis an economically and ecologically important demersal species inhabiting the Atlantic Ocean and the Mediterranean Sea; however, reproductive knowledge about this species, along the North African coast is still missing. Monthly samples were collected from November 2010 to October 2011 along the North Tunisian coast. Morphometric parameters were measured, and histological preparations of gonadic tissues provided detailed information on the reproductive biology. Ovary maturity data showed a protracted spawning season throughout the year, with peaks in January, April and August. In females ofM. merluccius, seasonal variability in weight and length were noticed, with higher values in the first part of the study period (November–April) than from May to October. Analysing separately these two periods, significant relationships were observed between gonadic maturation indices and the somatic and gonadic indices, suggesting a seasonal differential use of energy intake. From November to May the fish alternate the use of their energy for body growth and reserves for later uses (i.e fat, muscle and liver mass) or for gonadic growth. From June to October the energy is converted mainly into gonad weight and less to somatic growth. The maturity ogives obtained by macroscopic and histological maturity staging methods showed significant differences; however, in both cases the length at first maturity estimates were around 29 cm. Nonetheless, when selecting the main spawning period, theL50estimation was heavily reduced to 24 cm, suggesting careful attention in the selection of the samples to be used specially for fishery management purposes.

Reproductive life history of snakes in temperate regions: what are the differences between oviparous and viviparous species?

2019 ◽  
Vol 40 (3) ◽  
pp. 291-303
Author(s):  
Gisela Paola Bellini ◽  
Vanesa Arzamendia ◽  
Alejandro Raúl Giraudo
Keyword(s):  
Life History ◽  
Hydrological Cycle ◽  
Reproductive Potential ◽  
Reproductive Traits ◽  
Reproductive Mode ◽  
Raw Material ◽  
Genetic Characteristics ◽  
Reproductive Life ◽  
History Of ◽  
Reproductive Cycles

Abstract Studying life history (LH) allows a broader understanding of organisms and populations’ responses to their environments. Snakes display an immense diversity in terms of reproductive traits, which is reflected in LH traits. The aim of this study is to compare reproductive biology and morphological variables in viviparous and oviparous snakes of a temperate South American community. We studied nearly 1000 specimens of eight oviparous and seven viviparous species pertaining to the four taxonomic families that inhabit the Paraná basin floodplain. Dimorphic variables did not show a different tendency between oviparous and viviparous species. Our results showed that the reproductive mode determined some reproductive traits of a snake’s LH, such as reproductive frequency and reproductive potential. Oviparous snakes reproduce annually, while viviparous snakes reproduce biannually or multi-annually. All species showed seasonal reproductive cycles and no correlation between clutch size (fecundity) and maternal body size. The reproductive strategy of both oviparous and viviparous species of the Paraná River floodplain was to adjust their reproductive cycles to both hydrological cycle of the river and temperature regime. The reproductive traits under study are suggested to have been influenced by environmental factors as well as by genetic characteristics. The studied assemblage is the result of an admixture of evolutionarily distinct clades, each contributing a set of species with different reproductive traits. Although we do not ignore this fact, we emphasize the importance of studying reproductive LH as raw material for an integrative analysis.

A Method of Estimating Minimum Size Limits for Obtaining Maximum Yield

Copeia ◽  
1945 ◽  
Vol 1945 (2) ◽  
pp. 84 ◽  
Author(s):  
William E. Ricker
Keyword(s):  
Maximum Yield ◽  
Minimum Size ◽  
Size Limits

Reproductive traits ofMonochamus galloprovincialis(Coleoptera: Cerambycidae) under laboratory conditions

2006 ◽  
Vol 96 (3) ◽  
pp. 289-294 ◽  
Author(s):  
P. Naves ◽  
E. de Sousa ◽  
J.A. Quartau
Keyword(s):  
Secondary Forest ◽  
Reproductive Potential ◽  
Principal Component ◽  
Reproductive Traits ◽  
Bursaphelenchus Xylophilus ◽  
Egg Laying ◽  
Large Individual ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Laboratory Conditions

AbstractThe pine sawyerMonochamus galloprovincialis(Olivier) is the vector of the introduced pine wood nematodeBursaphelenchus xylophilus(Steiner & Bührer) Nickle in Portugal, and until recently was considered a secondary forest insect. Under laboratory conditions, a study of biological and reproductive traits of 37 insect pairs was conducted. The longevity of both sexes was similar, being 61.2±6.5 days for males and 64.0±6.3 days for females (mean±SE). Sixteen small-sized insects (22% of the population) died within 20 days and before starting to reproduce. The sexual maturation period (without egg laying) was 20.4±0.7 days (mean±SE), while the oviposition period lasted 54.0±4.2 days (mean±SE). The oviposition rate increased very quickly during the first weeks of life, peaking to almost two eggs per day during days 30–44, and gradually dropping in the following weeks. The females laid an average of 67.0±5.96 (mean±SE) eggs through their lives. The hatch rate was 92.6±1.0%; (mean±SE). There were large individual variations in longevity and fecundity parameters, and principal component analysis based on 16 morphological and biological parameters separated the breeding insects into four distinct groups. Almost half of the reproducing beetles were large-sized insects, with high longevity and fecundity traits. Overall, the reproductive potential of the Portuguese population ofM. galloprovincialisseems to be smaller than that described for otherMonochamusvectors of the pine wood nematode both in North America and Japan.

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