Puberty, Physical Maturity, and Relative Growth of the Female Humpback Whale, Megaptera nodosa (Bonnaterre), on the Western Australian Coast

1955 ◽  
Vol 6 (3) ◽  
pp. 315 ◽  
Author(s):  
RG Chittleborough
Keyword(s):  
Body Length ◽  
Sexual Maturity ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Relative Growth ◽  
Male And Female ◽  
The Mean ◽  
Sexually Mature ◽  
Western Australian

At puberty the mean body length of the female humpback whales on the Western Australian coast is 38.60 � 0.18 ft. It is demonstrated that this length gives a reliable means of calculating the proportion of sexually immature females in a series where the lengths are known. Sexual maturity (based upon the first pregnancy) may either follow immediately upon puberty or be delayed for a further year. At the approach of physical maturity (when epiphysial fusion begins) the mean body length is 45.08 � 0.29 ft. At this stage an average of 19 ovulations have occurred. On the available material, physical maturity is reached at a mean length of 44.34 � 0.72 ft, when close to 30 ovulations have occurred. Growth in body length of sexually mature females becomes very slow even before epiphysial fusion begins. The significance of the high number of ovulations before the attainment of physical maturity is discussed. The proportion of physically mature individuals amongst the females in recent catches off the Western Australian coast is extremely low (1.8 per cent. of 457 females examined). The lengths of male and female humpback whales at puberty, at the approach of physical maturity, and at physical maturity are compared.

Aspects of Reproduction in the Male Humpback Whale, Megaptera nodosa (Bonnaterre)

1955 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
RG Chittleborough
Keyword(s):  
Body Length ◽  
Low Fertility ◽  
Humpback Whales ◽  
Testis Weight ◽  
Activity Increase ◽  
Penis Length ◽  
The Mean ◽  
Considerable Individual Variation ◽  
Sexually Mature ◽  
Average Body

At puberty, male humpback whales off the Western Australian coast have an average body length of 36 ft 9 in. From histological examination of the testes, the extreme range of lengths at puberty is from 33 ft 4 in. to 40 ft 10 in. The mean testis weight at puberty is 2000 g. Following puberty, males are of low fertility for a period (possibly 1 yr) during which testis weight, tubule diameter, and spermatogenetic activity increase, before the attainment of full sexual maturity. The mean length of the penis at puberty is 3.5 ft, but owing to considerable individual variation the penis length alone is not a reliable criterion of puberty. In sexually mature males the penis length ranges from 3.2 to 6.2 ft. The proportion of fully physically mature males amongst those examined was very low (1.4 per cent.). The mean body length of those defined in this paper as approaching physical maturity was 41.90 � 0.35 ft, and that of the fully physically mature males was 42.97 �1.59 ft. The largest male examined (46.42 ft) showed no sign of epiphysial fusion. Changes in mean testis weight, mean diameter of testis tubules, and number of sperms in testes and vas deferens fluid have been followed at various stages of the life cycle. The variations of these characters in mature individuals have been examined for evidence of a seasonal cycle in male humpback whales; increasing testis weight and more active spermatogenesis are exhibited during winter months off Western Australia.

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.

Local Differences in the Body Proportions of the Lobster, Homarus americanus

1935 ◽  
Vol 1 (3) ◽  
pp. 213-226 ◽  
Author(s):  
W. Templeman
Keyword(s):  
Body Length ◽  
Sexual Maturity ◽  
Homarus Americanus ◽  
The Body ◽  
Body Proportions ◽  
Sexually Mature

The claws of males and the width and depth of abdomen of females increase at a higher rate than body length with approaching sexual maturity. Consequently for lobsters over 20 cm. in length males possess claws relatively larger and females an abdomen relatively wider and deeper in an area such as that near Pointe du Chêne where sexual maturity occurs at about 20 cm. than in that near Grand Manan where lobsters only become sexually mature at about 34 cm.

Fecundity of mooneye, Hiodon tergisus, in the Assiniboine River

1976 ◽  
Vol 54 (2) ◽  
pp. 156-161 ◽  
Author(s):  
C. L. Glenn ◽  
R. R. G. Williams
Keyword(s):  
Sexual Maturity ◽  
Ovarian Development ◽  
Age Groups ◽  
Gonadal Development ◽  
Spawning Activity ◽  
Total Fecundity ◽  
Annual Total ◽  
The Mean ◽  
October 17 ◽  
Sexually Mature

Age at sexual maturity, seasonal gonadal development, and fecundity estimates of mooneye were determined from 695 samples captured in the Assiniboine River between November 17, 1972, and November 2, 1973. Most mooneye became sexually mature in their 4th (III +) or 5th (IV +) year of life, with more males mature at age III + than females. During 1973, spawning began after May 8 and was completed by June 12. The peak spawning activity occurred during mid-May when water temperatures ranged from 10 to 13 °C. All age groups of sexually mature females had rapid ovarian development during the summer months with about 80% of maximum ovarian weight present by October 17. Ripe ova have a mean diameter of 1.98 ± 0.07 mm. The mean annual total fecundity of Assiniboine River mooneye was about 5000–9000 ova per female. The mean annual relative fecundity was about 2000–2400 ova per 100 g body weight.

Aerial Observations on the Humpback Whale, Megaptera nodosa (Bonnaterre), with Notes on Other Species

1953 ◽  
Vol 4 (2) ◽  
pp. 219 ◽  
Author(s):  
RG Chittleborough
Keyword(s):  
Western Australia ◽  
Great Increase ◽  
Humpback Whale ◽  
Mean Value ◽  
Humpback Whales ◽  
Maximum Frequency ◽  
Minke Whales ◽  
The Mean ◽  
Exmouth Gulf ◽  
Southward Migration

Aerial observations of humpback whales in the region of Point Cloates, Western Australia, during 1952 are recorded. The first southward-moving humpback whale was sighted on July 21, while decreasing numbers were seen moving northwards until early October. In 1952 the change from a predominantly northward migration of humpback whales to a southward migration occurred close to August 24. The speed of migration of a number of these whales is recorded, the mean value being 4.3 kt. A few humpback whale calves were sighted early in July and a peak in their occurrence in August suggests maximum frequency of parturition early in August. A very great increase in the occurrence of calves in the area late in the season suggests that female humpback whales rearing calves move southwards later than other individuals. Some evidence is presented that Exmouth Gulf is a nursery area. The presence of some killer, fin, blue, and minke whales in the area is noted.

scholarly journals New insights into prime Southern Ocean forage grounds for thriving Western Australian humpback whales

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sophie Bestley ◽  
Virginia Andrews-Goff ◽  
Esmee van Wijk ◽  
Stephen R. Rintoul ◽  
Michael C. Double ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Western Boundary ◽  
Boundary Current ◽  
Austral Spring ◽  
Partial Explanation ◽  
Migration Pathways ◽  
Western Australian ◽  
Feeding Grounds

Abstract Humpback whale populations migrate extensively between winter breeding grounds and summer feeding grounds, however known links to remote Antarctic feeding grounds remain limited in many cases. New satellite tracks detail humpback whale migration pathways from Western Australia into the Southern Ocean. These highlight a focal feeding area during austral spring and early summer at the southern Kerguelen plateau, in a western boundary current where a sharp northward turn and retroflection of ocean fronts occurs along the eastern plateau edge. The topographic steering of oceanographic features here likely supports a predictable, productive and persistent forage ground. The spatial distribution of whaling catches and Discovery era mark-recaptures confirms the importance of this region to Western Australian humpback whales since at least historical times. Movement modelling discriminates sex-related behaviours, with females moving faster during both transit and resident periods, which may be a consequence of size or indicate differential energetic requirements. Relatively short and directed migratory pathways overall, together with high-quality, reliable forage resources may provide a partial explanation for the ongoing strong recovery demonstrated by this population. The combination of new oceanographic information and movement data provides enhanced understanding of important biological processes, which are relevant within the context of the current spatial management and conservation efforts in the Southern Ocean.

Effects of environment and population density on the sea anemone Actinia tenebrosa

1984 ◽  
Vol 35 (6) ◽  
pp. 735 ◽  
Author(s):  
DJ Ayre
Keyword(s):  
Population Density ◽  
Intraspecific Competition ◽  
Sexual Maturity ◽  
Sex Ratios ◽  
Simple Relationship ◽  
Adult Size ◽  
The Mean ◽  
Breeding Seasons ◽  
Autumn And Winter ◽  
Western Australian

Within each of four Western Australian colonies of A. tenebrosa, adults developed gonads and brooded asexually produced juveniles during the summer months. The brooded juveniles were released throughout the year but most settlement occurred in autumn and winter. Dispersal of brooded juveniles was highly localized and they typically settled within 2 m of adults. Adults were sedentary and long- lived and recruitment rates were extremely low (about 1% per annum during the study period). Adult size and asexual fecundity differed markedly between colonies over three breeding seasons, but between-colony comparisons revealed no simple relationship between those characteristics. The mean number of juveniles per adult varied up to ninefold between colonies. Sex ratios deviated significantly from a ratio of 1 : 1 in samples from three colonies, and males predominated in two of these. Density-manipulation experiments revealed that intraspecific competition affected adult size, sexual maturity, asexual fecundity and rates of settlement and recruitment.

Determination of Age in the Humpback Whale, Megaptera nodosa (Bonnaterre)

1959 ◽  
Vol 10 (2) ◽  
pp. 125 ◽  
Author(s):  
RG Chittleborough
Keyword(s):  
East Coast ◽  
Age Distribution ◽  
Age Determination ◽  
Humpback Whales ◽  
Similar Distribution ◽  
The West ◽  
The Mean ◽  
Sexually Mature ◽  
Rate Of Accumulation

The use of baleen, ear plugs, and ovaries in the determination of age in humpback whales is described. From the evidence of baleen, the majority of humpback whales reach puberty at 4 or 5 years of age. The rate of accumulation of laminations in ear plugs is two laminations per year. The mean rate of ovulation in sexually mature females is 1.1 per year. Age determination upon the same sample of mature females by these two methods gives very similar distribution of ages. The age distribution within separate sexes from samples of mature humpback whales examined on the west and east coasts of Australia in 1957 are compared. The results indicate that the population migrating along the west coast is at present composed of younger individuals than that on the east coast of Australia.

Studies on the Ovaries of the Humback Whale, Megaptera nodosa (Bonnaterre), on the Western Australian Coast

1954 ◽  
Vol 5 (1) ◽  
pp. 35 ◽  
Author(s):  
RG Chittleborough
Keyword(s):  
Corpus Luteum ◽  
Sexual Maturity ◽  
Late Pregnancy ◽  
Humpback Whales ◽  
Corpora Lutea ◽  
Ovary Weight ◽  
Length Range ◽  
Foetal Life ◽  
Ovulatory Period ◽  
Western Australian

Observations on the increase of ovarian weight in the female humpback whale cover stages from late foetal life until after the attainment of sexual maturity. Variations in ovary weight during different phases of the reproductive cycle are recorded. Graafian follicles up to 0.13 mm in diameter have been found in the foetal ovary just prior to birth. These initially develop until from 11 to 29 mm (median value 20 mm) in diameter when the female reaches the maturing length range. At sexual maturity one of these follicles enlarges, exceeding 30 mm in diameter before rupture. After ovulation a corpus luteum is rapidly formed and if conception has taken place, this gland enlarges and remains active until parturition. After parturition there is rapid resorption of the corpus luteum to form a corpus albicans. Variations in the sizes and weights of functional corpora lutea are discussed. There is considerable reduction in the diameters of Graafian follicles in late pregnancy to a median value of 6 mm. After parturition follicles enlarge so that in the ovaries of females in late lactation the largest follicles once more range from 11 to 29 mm in diameter with a median value of 20 mm. In an ovulatory period of from June to November the maximum frequency of ovulations is in late July, though considerable numbers occur in August and September. On the availabIe evidence most female humpback whales ovulate only once in their ovulatory period, a few ovulate twice, and extremely few three times.

POTRET PERILAKU RELIGIUS MAHASISWA UIN SAYARIF HIDAYATULLAH JAKARTA

Al-Risalah ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 126-148
Author(s):  
Ay Maryani
Keyword(s):  
Religious Behavior ◽  
Male And Female ◽  
Mean Values ◽  
Significance Level ◽  
Average Value ◽  
Environment Variable ◽  
Independent Variable ◽  
The Mean ◽  
Gender Factor ◽  
Level 2

This study describes the religious behavior of UIN Syarif Hidayatullah Jakarta students. The variables used are internal and external environment as independent variable and religious behavior as dependent variable. The internal environment variable consists of gender factor, (male and female). The external environmental variables comprise the faculty environment, the present resident and the place to grow. The present resident consist of dormitories, boarding houses and parents' homes and the place to grow consist of urban and rural environment. Religious behavior variables consist of habluminallah behavior and habluminannas behavior. Habluminallah's behavior measured by (1) knowledge of faith and worship, (2) attitudes toward faith and worship, and (3) practice of faith and worship. The habluminannas variable measured by (1) Islamic behavior for them self, like honest, discipline and good work / studyethics, trust and concern on legality, (2) Islamic behavior with others, like generous, cooperation, caring, respect to the people's rights and tolerance and (3) Islamic behavior for the natural surroundings, like love of nature and nature conservation efforts. The methodology used was (1) Statistical descriptive, (2) MANOVA (Multivariate Analysis of Variance) and (3) Independent sample t-test. The results showed the religious behavior UIN Syarif Hidayatullah Jakarta students has a very good category. This is indicated by the mean values for the behavior of haluminallah and habluminannas of 158.85 and 178.76,  espectively. The average value of habluminallah behaviour in the range of values "145-180" with the category of "very good" and habluminannas behavior in the range value "165-205" with the category "very good. Habluminallah and habluminannas behavior are different for each faculty. This is indicated by the significance level of Pillai Trace, Wilk Lambda, Hotelling Trace, Roy's Largest Root of 0.00 (<0.05). Habluminallah and habluminannas behavior are the same for respondents who live in dormitories, boarding houses, and parents' homes. This is indicated by the value of F test and significance at Wilk's Lambda respectively for 2.055 and 0.085 (>0.05). Habluminallah and habluminannas behaviors are similar for urban and rural respondents. This is known from the sig level. (2-tailed) for habluminallah and habluminannas behavior of 0.317 and 0.245 (> 0.05), respectively. Habluminallah and habluminannas behaviors are similar for male and female. This is known from the sig level. (2-tailed) for habluminallah and habluminannas behavior of 0.950 and 0.307 (> 0.05),respectively. The results of this study are expected to be used to develop university policies that can enhance the Islamic values of UIN Syarif Hidayatullah Jakarta.

Sign in / Sign up

Export Citation Format

Share Document