Role of spawning condition in the determination of the reproductive traits of spring- and autumn-spawning Atlantic herring from the southern Gulf of St. Lawrence

1993 ◽  
Vol 71 (2) ◽  
pp. 309-317 ◽  
Author(s):  
Rodney G. Bradford

Mature spring-spawning (May–June) and autumn-spawning (August–September) herring differ in total weight. Autumn herring have both heavier gonads and higher somatic weights at length. Both the residual levels of storage lipids and somatic weight at length, corrected for storage lipid, are higher in autumn than in spring. Within spawning seasons, males and females deplete the same amount of storage energy. Percent somatic lipid content is positively correlated with body size during spring but shows no relationship to body size in autumn. These patterns indicate that the relative allocation of storage energy to reproduction differs with spawning season. Spring spawners (lengthy gonad maturation period) allocate proportionally more storage energy to routine and active metabolism than autumn spawners (brief gonad maturation period). The low intercept and steep slope of the gonad weight – length relationship for spring spawners reflect the interaction between decreasing metabolic rate with body size and increasing storage energy capacity with body size. Egg weight is unrelated to the parent's somatic lipid content for either spawning group. Spawning history (recruit versus repeat spawning) has only a minor influence on egg weight.

1992 ◽  
Vol 49 (10) ◽  
pp. 2045-2054 ◽  
Author(s):  
Rodney G. Bradford ◽  
Robert L. Stephenson

Egg weight varies among northwest Atlantic herring (Clupea harengus) populations that spawn in different seasons (n = 12), but the range in weights is less than half of that known for northeast Atlantic populations. Egg weights were similar for both spring (May–June)- and autumn (August–October)-spawning herring (1.06 ×) and most dissimilar between spring- and summer (July)-spawning herring (1.21 ×). Mean population egg weights were not correlated with temperature either at spawning or for the last 2 mo of the egg development period. The product of egg weight and fecundity (standardized to length) differed between spring- and autumn-spawning herring of the southern Gulf of St. Lawrence. Spring-spawners, particularly smaller fish [Formula: see text], have lower ripe ovary weights than do autumn-spawning herring. Differences between spawning seasons in the relative allocation of storage energy to gonad and metabolism, a process mediated by the duration of the gonad maturation period, are the likely basis for the observed patterns.


Author(s):  
Carolina Manzano ◽  
Eduardo G. Virla ◽  
Maria V. Coll Araoz ◽  
Erica Luft-Albarracin

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lingbin Liu ◽  
Zhifu Cui ◽  
Qihai Xiao ◽  
Haihan Zhang ◽  
Xiaoling Zhao ◽  
...  

The aim of the study was to investigateGDF9gene polymorphisms and their association with reproductive traits in chicken using DNA sequencing. A total of 279 Dongxiang blue-shelled (DX) chickens and 232 Luhua (LH) chickens were used for validation. We detected 15 single nucleotide polymorphisms (SNPs): nine SNPs were previously unreported in chicken, two were missense mutations, and only three exhibited significant associations with reproductive traits. G.17156387C>T was significantly associated with age at first egg (AFE) and weight of first egg (WFE) in both breeds. Birds carrying the CC genotype exhibited higher AFE and WFE values than those with the TT genotype. The SNP g.17156427A>G exhibited an association with egg weight at 300 days of age (EWTA) in DX but not in LH chickens. The SNP g.17156703A>C affected the AFE and EN (total number of eggs at 300 days of age) in DX chickens. In addition, certain diplotypes significantly affected AFE, BWTA (body weight at 300 days of age), and EN in both breeds. RT-PCR results showed that theGDF9gene was highly expressed in stroma with cortical follicles (STR) and prehierarchal follicles. These results provided further evidence that theGDF9gene is involved in determining reproductive traits in chicken.


Zootaxa ◽  
2012 ◽  
Vol 3288 (1) ◽  
pp. 1 ◽  
Author(s):  
S. BLAIR HEDGES ◽  
CAITLIN E. CONN

Neotropical skinks are unique among lizards and other vertebrates in their degree of convergence, in reproductive traits,with eutherian mammals. They have also been famously difficult to classify into species, largely because of a conservativebody plan and paucity of conventional diagnostic characters. Currently there are 26 recognized species, six of which occuronly on Caribbean islands. All are placed in a single genus, Mabuya. We conducted a systematic revision of Neotropicalskinks using both conventional and unconventional morphological characters, supplemented by DNA sequence analyses.We define 61 species grouped into 16 clades, recognized here as genera. They include three available generic names(Copeoglossum, Mabuya, and Spondylurus) and 13 new genera: Alinea gen. nov., Aspronema gen. nov., Brasiliscincusgen. nov., Capitellum gen. nov., Exila gen. nov., Manciola gen. nov., Maracaiba gen. nov., Marisora gen. nov., Noto-mabuya gen. nov., Orosaura gen. nov., Panopa gen. nov., Psychosaura gen. nov., and Varzea gen. nov. These 16 generaof skinks form a monophyletic group and are placed in the Subfamily Mabuyinae of the skink Family Mabuyidae. Sixother skink families are recognized: Acontidae, Egerniidae, Eugongylidae, Lygosomidae, Scincidae, and Sphenomorphi-dae. We describe three new subfamilies of Mabuyidae: Chioniniinae subfam. nov., Dasiinae subfam. nov., and Trachyl-epidinae subfam. nov. We describe 24 new species of mabuyines: Capitellum mariagalantae sp. nov., Capitellumparvicruzae sp. nov., Copeoglossum aurae sp. nov., Copeoglossum margaritae sp. nov., Copeoglossum redondae sp.nov., Mabuya cochonae sp. nov., Mabuya desiradae sp. nov., Mabuya grandisterrae sp. nov., Mabuya guadeloupae sp.nov., Mabuya hispaniolae sp. nov., Mabuya montserratae sp. nov., Marisora aurulae sp. nov., Marisora magnacornaesp. nov., Marisora roatanae sp. nov., Spondylurus anegadae sp. nov., Spondylurus culebrae sp. nov., Spondylurus caico-sae sp. nov., Spondylurus haitiae sp. nov., Spondylurus magnacruzae sp. nov., Spondylurus martinae sp. nov., Spondy-lurus monae sp. nov., Spondylurus monitae sp. nov., Spondylurus powelli sp. nov., and Spondylurus turksae sp. nov. Wealso resurrect 10 species from synonymies: Alinea lanceolata comb. nov., Alinea luciae comb. nov., Capitellum metalli-cum comb. nov., Mabuya dominicana, Marisora alliacea comb. nov., Marisora brachypoda comb. nov., Spondylurusfulgidus comb. nov., Spondylurus nitidus comb. nov., Spondylurus semitaeniatus comb. nov., and Spondylurus spilonotuscomb. nov. Of the 61 total species of mabuyine skinks, 39 occur on Caribbean islands, 38 are endemic to those islands,and 33 of those occur in the West Indies. Most species on Caribbean islands are allopatric, single-island endemics, al-though three species are known from Hispaniola, three from St. Thomas, and two from Culebra, St. Croix, Salt Island,Martinique, the southern Lesser Antilles, Trinidad, and Tobago. Co-occurring species typically differ in body size and be-long to different genera. Three ecomorphs are described to account for associations of ecology and morphology: terrestri-al, scansorial, and cryptozoic. Parturition occurs at the transition between the dry and wet seasons, and the number ofyoung (1–7) is correlated with body size and taxonomic group. Molecular phylogenies indicate the presence of many un-named species in Middle and South America. A molecular timetree shows that mabuyines dispersed from Africa to SouthAmerica 18 (25–9) million years ago, and that diversification occurred initially in South America but soon led to coloni-zation of Caribbean islands and Middle America. The six genera present on Caribbean islands each represent separate dis-persals, over water, from the mainland during the last 10 million years. Considerable dispersal and speciation alsooccurred on and among Caribbean islands, probably enhanced by Pleistocene glacial cycles and their concomitant sea lev-el changes. Based on IUCN Redlist criteria, all of the 38 endemic Caribbean island species are threatened with extinction.Twenty-seven species (71%) are Critically Endangered, six species (16%) are Endangered, and five species (13%) are Vul-nerable. Sixteen of the Critically Endangered species are extinct, or possibly extinct, because of human activities duringthe last two centuries. Several of the surviving species are near extinction and in need of immediate protection. Analysisof collection records indicates that the decline or loss of 14 skink species can be attributed to predation by the Small IndianMongoose. That invasive predator was introduced as a biological control of rats in sugar cane fields in the late nineteenthcentury (1872–1900), immediately resulting in a mass extinction of skinks and other reptiles. The ground-dwelling and diurnal habits of skinks have made them particularly susceptible to mongoose predation.


Author(s):  
R.J. Henderson ◽  
S.M. Almatar

It is well established that the lipid content of the herring Clupea harengus from the waters around the British Isles and Ireland undergoes a marked seasonal cycle, being highest during the summer months of active feeding and lowest after a winter fast (Wood, 1958; lies & Wood, 1965; Lovern & Wood, 1937; Molloy & Cullen, 1981; Wallace, 1986). In the case of spring-spawning herring, the minimum lipid content coincides with the spawning period and the depletion of lipid over winter corresponds with the development of gonads (Lovern & Wood, 1937).


Author(s):  
Urszula Janas ◽  
Anna Mańkucka

Body size and reproductive traits ofis a species of prawn new (since 2000) to the southern Baltic. The aim of this study was to find out whether there are differences in the sizes of individuals and in the reproductive traits of


2004 ◽  
Vol 61 (10) ◽  
pp. 1900-1917 ◽  
Author(s):  
C Tara Marshall ◽  
Coby L Needle ◽  
Nathalia A Yaragina ◽  
Adnan M Ajiad ◽  
Evgeny Gusev

To evaluate interstock differences in condition, it would be advantageous to develop stock-level condition indices from standardized databases on weight and length. This study describes a method for estimating stock-level condition when individual-level observations on length and weight are not easily accessible. For each year in a 56-year time series (1946–2001) for Northeast Arctic cod (Gadus morhua), pseudo-observations of weight and length were generated by pairing the Norwegian and Russian values for weight-at-age provided annually to the assessment working group with estimates of length-at-age derived from the same databases. A weight–length relationship fit to each year was then used to predict weight-at-length, i.e., girth, for a range of standard lengths (30–120 cm). This index was uncorrelated with both the liver condition index and the abundance of Barents Sea capelin (Mallotus villosus), suggesting that at the stock level, the girth of cod is not necessarily indicative of the magnitude of stored energy reserves. Partitioning body size into length-at-age and girth revealed long-term trends in body size. In particular, large/old cod showed substantially higher values of both length-at-age and girth that could be the result of long-term increases in fishing mortality.


Author(s):  
M. Sarma ◽  
R. Islam ◽  
M. K. Borah ◽  
P. Sharma ◽  
J. D. Mahanta ◽  
...  

A study was conducted covering a total of one hundred chicken farmers in tribal dominated Boko Block of Kamrup district in Assam to assess different productive and reproductive traits of Desi, Vanaraja and Srinidhi birds under field condition. Information was obtained on mean body weight at various ages, age at first egg, annual egg production, fertility and hatchability and mortality rate. Body weight, egg production and egg weight were significantly (P£0.05) higher in Vanaraja and Srinidhi birds compared to Desi chicken. The age at first egg was significantly (P£0.05) higher in Desi chicken while compared with Vanaraja and Srinidhi under traditional system of management. However no significant (P£0.05) difference was found between Vanaraja and Srinidhi in their body weight and egg production at various ages. Higher mortality percent in Vanaraja (12.23±1.62) and Srinidhi (11.34±1.23) were recorded during 0 to 5 week. No significant (P£0.05) differences were found among all three groups of birds in fertility and hatchability.


2010 ◽  
Vol 5 (3) ◽  
pp. 391-395 ◽  
Author(s):  
Katarina Ljubisavljević ◽  
Georg Džukić ◽  
Miloš Kalezić

AbstractWe present data on the female reproductive traits of the Balkan wall lizard in the Deliblato Sand, a large continental sandland in the Pannonian area in the northwestern periphery of the species range. The clutch and egg characteristics of the population were investigated on the basis of clutches laid in laboratory conditions by gravid females captured in one locality. Balkan wall lizards produced at least two clutches in a breeding season. Individual females laid clutches of commonly two (range 1–4) eggs. The female body size had no effect on clutch and egg size. There was no trade-off between egg size and clutch size.


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