Age at sexual maturity of male and female banana weevils, Cosmopolites sordidus Germar (Coleoptera: Curculionidae)

2017 ◽  
Vol 99 (1) ◽  
pp. 2-8
Author(s):  
Richard P. Uzakah
Keyword(s):  
Sexual Maturity ◽  
Cosmopolites Sordidus ◽  
Male And Female

A COMPARISON OF VARIATIONS IN PLASMA LUTEINIZING HORMONE CONCENTRATIONS IN MALE AND FEMALE DOMESTIC CHICKENS (GALLUS DOMESTICUS) FROM HATCH TO SEXUAL MATURITY

1975 ◽  
Vol 67 (2) ◽  
pp. 211-223 ◽  
Author(s):  
P. J. SHARP
Keyword(s):  
Luteinizing Hormone ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Gallus Domesticus ◽  
Parallel Study ◽  
Stages Of Development ◽  
Male And Female ◽  
The Mean ◽  
Lh Secretion

SUMMARY Changes in plasma LH concentrations were followed in chickens of both sexes from hatch to sexual maturity using a radioimmunoassay. Mean levels of LH were lower in the females than in the males at all stages of development. These levels rose rapidly in both sexes during the first week after hatch to maxima of 6·5 ± 1·2 (s.e.m.) ng/ml (n = 6) in the males and 4·6 ± 0·6 ng/ml (n = 6) in the females. Thereafter levels of the hormone in the circulation stabilized in the males but fell over a period of 1 or 2 weeks in the females to 2·5–3 ng/ml. Plasma LH levels started to rise steeply in both sexes when they were between 16 and 19 weeks old at the same time as there was an increase in the rate of comb growth. Afterwards in six of the males studied in detail the mean plasma LH level rose significantly (P < 0·01) over a period of 5–8 weeks from 8·1 ± 1·2 to 13·2 ± 1·9 ng/ml. In a parallel study on six females the rate of LH secretion increased for approximately 3 weeks and then decreased for about the same period forming a prepubertal LH peak. The first eggs were laid between 22 and 25 weeks of age when mean plasma LH levels had fallen to about 1·8 ng/ml. The mean plasma LH level in these hens when they were laying (1·8 ± 0·3 ng/ml) was significantly lower (P < 0·01) than when they were sexually immature (2·7 ± 0·3 ng/ml). The duration of the period of rapid comb growth in each bird was closely related in the males to the time during which prepubertal LH levels were rising rapidly, and in the females to the duration of the prepubertal LH peak. Differences in mean plasma LH concentrations in individual birds of either sex before the onset of puberty appeared to be related to subsequent reproductive performance.

scholarly journals EVALUATION OF PURE AND CROSSBRED PARENT STOCK PULLETS

2021 ◽  
Vol 22 (1) ◽  
pp. 10-14
Author(s):  
J. A. ADENOWO ◽  
S. S. I. OMEJE ◽  
N. I. DIM
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Egg Weight ◽  
Male And Female ◽  
Phenotypic Correlations ◽  
Parent Stock ◽  
Additive Inheritance

The relationships between egg weight, body weight and sexual maturity and their inheritance were studied in the F1 of two grandparent strains of laying birds. Each strain had two lines. Data used for analyses comprised body weight at first egg, 30 weeks and 40 weeks of age (BFE, B30 and B40); weight of first egg (WFE), weight of egg at 30 weeks and 40 weeks (W30, W40) and age of birds at first egg (AFE). Phenotypic correlations between AFE and BFE, AFE and WFE and between WFE and BFE were 0.45 and 0.40; 0.96 and 0.11, 0.65 and 0.85 for male and female lines respectively. While AFE generally showed additive inheritance which was sire influenced, BFE and WFE were line dependent. The crossbred groups however, appeared to be at advantage over the purebreds in respect of these three traits.

scholarly journals Memoirs: The Structure and Development of the Thymus in Fish, with special reference to Salmo Fario

1927 ◽  
Vol s2-71 (281) ◽  
pp. 113-145
Author(s):  
RUTH DEANESLY
Keyword(s):  
Epithelial Cells ◽  
Sexual Maturity ◽  
Comparative Anatomy ◽  
Male And Female ◽  
Laboratory Facilities ◽  
Vascular Elements ◽  
Mucus Gland ◽  
University Museum ◽  
Thymus Cells ◽  
Adult Thymus

1. Three thymus ‘buds’ can be originally distinguished in trout, in the thickened epithelium above the 1st, 2nd, and 3rd gill-arches, at the junction of ectoderm and endoderm. 2. Differentiation spreads almost immediately into the ectoderm between the original buds, and a continuous differentiating area is formed which is partly ectodermal and partly endodermal. 3. Repeated division of the epithelial cells, beginning a few days before hatching, gives rise to the small thymus cells. The latter are not derived from immigrating lymphocytes, as has been stated by Hammar and Maximow. 4. Emigration of thymus cells may take place at all ages. 5. Immigration of connective tissue and vascular elements from the mesoderm begins just before hatching, but such immigration is not active till a week later. 6. The large elements in the adult thymus are mesodermal, with the exception of the epithelial cells at the edges, and a few mucus gland-cells, similar to those occurring in the ordinary epithelium. 7. In both male and female trout the thymus undergoes almost complete involution, when the fish is between 2 and 2½ years old. There is no evidence that the time of involution is connected with the time of sexual maturity. The work was done in the Department of Zoology and Comparative Anatomy, University Museum, Oxford. My thanks are due to Professor E. S. Goodrich, F.R.S., for reading this paper and making suggestions, and for laboratory facilities, and also to Mr. D. F. Leney of the Surrey Trout Farm for supplying and fixing material. A grant towards the expenses of the work was made by the Christopher Welch Trustees.

scholarly journals Spatial and temporal length distribution of Zungaro zungaro caught in the Orinoco River Basin of Colombia

2016 ◽  
pp. 5211-5221
Author(s):  
Hernando Ramírez-Gil
Keyword(s):  
River Basin ◽  
Sexual Maturity ◽  
Length Distribution ◽  
Historical Records ◽  
Male And Female ◽  
Orinoco River ◽  
Size At Sexual Maturity ◽  
Males And Females ◽  
Average Size ◽  
River Drainages

ABSTRACT Objetive. To determine the effect of fishing on capture size of both male and female Zungaro zungaro catfish, historical records of size and spatial distribution of the species were analyzed from the Orinoco Basin in Colombian. Materials and methods. Information was collected by sampling fishing port landings in the region between 1979 and 2011. Each specimen was measured, weighed and sexed. With 5411 records, the average size at capture were compared in time and among the different ports. Size at 50% maturity was estimated by quinquennium. Results. The average commercial capture sizes of Z. zungaro ranged from 35 to 161 cm standard length, with differences between males and females. From 1979 to 2011, in Puerto Lopez, the size at sexual maturity decreased from 123.8 to 83.4 cm in females and from 93.3 to 61 in males. In the annual cycle the greater average capture size in females was from April to July and for males from May to June. Average annual length is higher in the higher parts of the Meta and Guaviare river drainages. In the last quinquennium the size at 50% maturity had fallen 10 cm in females and 5 cm in males and it is higher than the average capture size. Conclusions. Populations of Z. zungaro in the Colombian Orinoco River Basin have been affected by overfishing and selective fishing of females. RESUMEN Objetivo. Determinar el grado de afección en la población de Zungaro zungaro a partir del análisis del comportamiento histórico y espacial de las tallas de captura de hembras y machos de la especie en la Orinoquia colombiana. Materiales y métodos. La información fue colectada mediante muestreos a los desembarcos en puertos pesqueros de la región entre 1979 y 2011. Cada ejemplar fue medido, pesado y sexado. Con 5411 registros, se estableció la distribución de las tallas medias de captura, que se compararon en el tiempo y entre los diferentes puertos. Se estimó la talla de madurez gonadal (TMG) por quinquenios. Resultados. El rango de las tallas de captura comercial Z. zungaro fue de 35 a 161 cm longitud estándar (LS), con diferencia entre machos y hembras. Entre los años 1979 a 2011, en Puerto López, la talla promedio de captura anual (LS) disminuyó de 123.8 a 83.4 cm en hembras y de 93.3 a 61 cm en machos. En el ciclo anual la mayor talla promedio de captura de hembras se presenta en abril a julio y de machos en mayo y junio. La talla promedio de captura anual (TPCA) es superior en las partes altas de los ríos Meta y Guaviare. En el último quinquenio la TMG ha disminuido 10 cm en las hembras y cinco cm en los machos y es superior a la TPCA. Conclusiones. Hay afectación sobre la población explotada de Z. zungaro por sobrepesca por crecimiento y pesca selectiva de hembras en la Orinoquia colombiana.

Variation with Fish Length, Sex, Stage of Sexual Maturity, and Season in the Appearance and Volume of the Drumming Muscles of the Swim-Bladder in the Haddock, Melanogrammus aeglefinus (L.)

1958 ◽  
Vol 15 (3) ◽  
pp. 355-390 ◽  
Author(s):  
Wilfred Templeman ◽  
V. M. Hodder
Keyword(s):  
Sexual Maturity ◽  
Low Frequency ◽  
Mature Male ◽  
Melanogrammus Aeglefinus ◽  
Fish Length ◽  
Swim Bladder ◽  
Secondary Importance ◽  
Spawning Period ◽  
Male And Female ◽  
The Difference

Observations made as early as 1947 and data collected in 1953 to 1954 and 1956 to 1957 indicate that there is considerable variation in the size and appearance of the drumming muscles of the swim-bladder of haddock with fish length, sex, sexual maturity, and season on the Grand Bank and St. Pierre Bank. For haddock of the same length the data indicate that the drumming muscles of mature male haddock are larger than those of immature males and also of immature and mature females of the same length. In addition the data indicate that a periodicity is exhibited in the size of the muscles of the mature male, the muscles being nearly twice as large during the pre-spawning and spawning period in May and June as they are in October and November. This phenomenon does not occur in female haddock, the drumming muscles of which are considerably smaller than those of male fish of the same size and show no variation in size with the season.It is suggested that the difference in size of the drumming muscles of male and female haddock can serve as a means of determining the sex of haddock landed in the gutted condition by commercial trawlers, at least for the mature fish which make up the bulk of the commercial trawlers' catches. There is some difference between male and female haddock in the colour of drumming muscles, but this seems to be of secondary importance for distinguishing between the sexes.Male haddock probably use the drumming muscles chiefly to produce low-frequency swim-bladder sounds which serve as rallying calls for female and other male haddock to join in spawning activities.

Temporal and ontogenic variations of diet of the goldblotch grouper Epinephelus costae (Serranidae) in the eastern coast of Algeria

2016 ◽  
Vol 97 (2) ◽  
pp. 259-267
Author(s):  
Raouf Zaidi ◽  
Farid Derbal ◽  
M. Hichem Kara
Keyword(s):  
Sexual Maturity ◽  
Feeding Habits ◽  
Eastern Coast ◽  
Female Size ◽  
Relative Importance ◽  
Diverse Range ◽  
Male And Female ◽  
Qualitative And Quantitative ◽  
Index Of Relative Importance ◽  
Digestive Contents

The diet of the goldblotch grouper Epinephelus costae of the eastern coast of Algeria was studied from March 2011 to February 2012. A total of 275 individuals, whose total length varied between 21.1 and 79.79 cm and weight between 103.13 and 5390.00 g, were examined. The index of relative importance (%IRI) combining the three main descriptors of the presence of different ingested prey (%F, %N, %W) was used to characterize the relative importance of different food taxa. Qualitative and quantitative variations in diet were studied according to sexual maturity (immature and mature), sex (male and female), size (small, medium and large) and seasons. The average annual digestive vacuity is 17.82%. It does not vary according to sex, size or maturity, but is different between summer and winter. Qualitative analysis of digestive contents reveals a fairly diverse range of predation with 319 prey counted for a total weight of 934.85 g, which corresponds to an average number (Nm) and weight (Wm) of 1.4 and 4.14 g respectively. This species feeds on benthopelagic prey composed mainly of bony fish (%IRI = 76.16), pancrustacea (%IRI = 16.14) and molluscs (%IRI = 6.24). All other prey were accessory (plants) or accidental (annelids). Significant differences in feeding habits occur according to seasons and fish size.

The life history of Halosaccion ramentaceum

1981 ◽  
Vol 59 (4) ◽  
pp. 433-436 ◽  
Author(s):  
John P. van der Meer
Keyword(s):  
Life History ◽  
Chromosome Number ◽  
Sexual Maturity ◽  
Mutant Phenotype ◽  
Sexual Cycle ◽  
Palmaria Palmata ◽  
Male And Female ◽  
Haploid Male ◽  
History Of ◽  
Mendelian Transmission

The complete life history of Halosaccion ramentaceum has been determined. It is very similar to that of Palmaria palmata, consisting of haploid male and female gametophytes alternating with a diploid tetrasporophyte. As for P. palmata, there is no carposporophyte. Male and female gametophytes attain sexual maturity almost a generation apart. Whereas male plants require approximately 1 year's growth before producing spermatia, female gametophytes are microscopic and reach sexual maturity only a few days after tetraspore germination. The diploid tetrasporophyte initiates its development on the female, but almost immediately forms an independent holdfast on the substratum beside the female. The first diploid fronds arise from that holdfast after it is well established.The existence of a complete sexual cycle was proven by demonstrating: fertilization of trichogynes by spermatia; meiosis in tetrasporangia, with a chromosome number of n = ~24 in gametophytes and 2n = ~48 in tetrasporophytes; and by documenting the Mendelian transmission of a mutant phenotype from the male parent to the F1 gametophytes.

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