scholarly journals The vascular filaments on the pelvic limbs of Lepidosiren, their function and evolutionary significance

1929 ◽  
Vol 105 (739) ◽  
pp. 484-493 ◽  
Keyword(s):  
Breeding Season ◽  
Evolutionary Significance ◽  
Breeding Period ◽  
Vital Activity ◽  
Male Fish ◽  
Probable Function ◽  
Gran Chaco ◽  
Fish Remains ◽  
Eggs And Larvae

In 1900 Prof. J. Graham Kerr published the results of his investigations into the habits and reproduction of Lepidosiren in the swamps of the Gran Chaco, in Paraguay (' Phil. Trans.,' Series B, vol. 292). He found that just before the breeding season papillæ which occur on the pelvic limbs of the male rapidly develop into long, bright-red, vascular filaments. These persist throughout the breeding period, during which the male fish remains in the Nesting burrow with the eggs and larvæ. After this period the filaments disappear, by atrophy of the tissues and disintegration, not by absorption. Neither filaments nor papillæ usually occur on the pelvic Iimbs of the female, but papillæ in a very rudimentary condition occur occasionally in female specimens, and, judging from the analogy of sex-limited characters in other vertebrates these specimens are possibly the oldest, and perhaps no longer fertile. Prof. Graham Kerr discusses the question of the function of these vascular filaments in the male. Sir Ray Lankester had suggested that they were accessory organs of respiration; Dr. Hans Gadow that they might be spawning brushes tor spreading the semen; Graham Kerr himself thought they might be due to "the intense vital activity associated with reproduction," but on further consideration agreed with Sir Ray Lankester that respiration was their most probable function.

scholarly journals Female song in the Cyprus Wheatear Oenanthe cypriaca

2021 ◽  
Author(s):  
Robert Patchett ◽  
Alexander N. G. Kirschel ◽  
Joanna Robins King ◽  
Patrick Styles ◽  
Will Cresswell
Keyword(s):  
Breeding Season ◽  
Bird Species ◽  
Breeding Period ◽  
Territorial Defence ◽  
Multiple Functions ◽  
Male Song ◽  
Female Song ◽  
Mate Acquisition

AbstractFemale song is widespread across bird species yet rarely reported. Here, we report the first observations and description of female song in the Cyprus Wheatear Oenanthe cypriaca and compare it to male song through the breeding season. Twenty-five percent of colour-ringed females were observed singing at least once, predominantly in April, compared to 71% of males that continued singing through the breeding period. We suggest that female song may have multiple functions in this species, but it may be especially important in territorial defence and mate acquisition.

scholarly journals Abundance estimate and seasonal patterns of grey seal (Halichoerus grypus) occurrence in Brittany, France, as assessed by photo-identification and capture–mark–recapture

2007 ◽  
Vol 87 (1) ◽  
pp. 365-372 ◽  
Author(s):  
Maureen Gerondeau ◽  
Christophe Barbraud ◽  
Vincent Ridoux ◽  
Cécile Vincent
Keyword(s):  
Breeding Season ◽  
Site Fidelity ◽  
Seasonal Abundance ◽  
Breeding Period ◽  
Home Ranges ◽  
Grey Seal ◽  
British Isles ◽  
Mark Recapture ◽  
Abundance Estimate ◽  
Photo Identification

It has been suggested that the large grey seal colonies around the British Isles form local populations within a metapopulation, and that seal movements outside the breeding season lead to considerable overlap between individual home ranges. Individual behaviour and population dynamics of small peripheral colonies may also play a role in the metapopulation. We studied the French grey seal colony of the Molène archipelago, at the southern-most limit of the species' range. We analysed photo-identification data with capture–mark–recapture techniques in order to estimate the total seasonal abundance of grey seals in the archipelago and to quantify the seasonal rates of occurrence or movements of male and female seals. We found that between 58 (95% confidence interval: 48–71) and 98 (95% CI: 75–175) individuals hauled out in the archipelago during the summers of 1999 and 2000. The use of multistate models allowed the assessment of seasonal site fidelity and indicated that it varied between key periods of the annual cycle, particularly for females. Males showed a constant fidelity rate of 56% from one season to another. Hence, even though they showed high inter-annual site fidelity, they did not seem to have a preferred season for using the archipelago. On the contrary, female grey seals showed the highest site fidelity between moult and summer (around 80%), and the lowest fidelity between summer and the breeding period (34–43%). Thus, females seem to use the Molène archipelago preferentially in summer and leave the site before the breeding season, which explains the very low local pup production. Philopatry may explain this pre-breeding emigration, and we suggest that most grey seals observed in the Molène archipelago were born and breed in other local breeding populations, probably the south-western British Isles.

Influence of lambing date on subsequent ovarian cyclicity and ovulation rate in ewes

1997 ◽  
Vol 65 (1) ◽  
pp. 75-81 ◽  
Author(s):  
L. M. Mitchell ◽  
M. E. King ◽  
R. P. Aitken ◽  
J. M. Wallace
Keyword(s):  
Breeding Season ◽  
Ovulation Rate ◽  
Breeding Period ◽  
Ovarian Activity ◽  
Blood Samples ◽  
Natural Breeding ◽  
Seasonal Decline ◽  
Ovarian Cyclicity ◽  
Ovarian Cycles ◽  
Subsequent Onset

AbstractThe effect of lambing date on the subsequent onset and duration of ovarian cyclicity in Mule (Bluefaced Leicester × Scottish Blackface) ewes was investigated. Nineteen ewes which had lambed in January (16 January 1993 (s.e. 3 days)) and been weaned in February-March and 22 comparable ewes which had lambed in May (14 May 1993 (s.e. 2 days)) and been weaned on 23 August were maintained at pasture as two isolated groups. A raddled vasectomized ram was continually present with each group from 14 July 1993 to 26 May 1994 and marked (oestrous) ewes were recorded twice weekly. Ovarian activity was assessed by measuring peripheral progesterone concentrations in blood samples collected twice weekly and by laparoscopic viewing of the ovaries of all ewes during October, January and March. The onset and duration of ovarian activity were significantly affected by the previous lambing date. For January and May lambing ewes, mean dates of onset were 5 September 1993 (s.e. 2 days) v. 25 September 1993 (s.e. 4 days) (P < 0·001) and of cessation were 5 April 1994 (s.e. 5 days) v. 10 April 1994 (s.e. 3 days). Mean durations of ovarian activity were 212 (s.e. 6) and 195 (s.e. 5) days (P < 0·05) during which 12·4 (s.e. 0·29) and 11·5 (s.e. 0·38) ovarian cycles respectively were recorded. Ovulation rate was not affected by previous lambing date but was significantly lower in March compared with October (January lambing ewes 1·7 (s.e. 0·1) v. 2·3 (s.e. 0·1) (P < 0·001); May lambing ewes 1·6 (s.e. 0·1) v. 2·1 (s.e. 0·1) (P < 0·01)). Results demonstrate that (i) Mule ewes have a potential breeding season of up to 8 months duration; (ii) the onset and duration of ovarian activity can be influenced by previous lambing date; and (Hi) a seasonal decline in ovulation rate may, in practical terms, result in a lower lambing percentage for animals bred towards the end of their natural breeding period.

scholarly journals Observations on Patella Vulgata. Part I. Sex-Phenomena, Breeding and Shell-Growth

1928 ◽  
Vol 15 (3) ◽  
pp. 851-862 ◽  
Author(s):  
J. H. Orton
Keyword(s):  
Breeding Season ◽  
Shell Growth ◽  
Sex Change ◽  
Chromosome Constitution ◽  
Breeding Period ◽  
Patella Vulgata ◽  
The Future ◽  
Different Seasons ◽  
Metabolic Conditions

SUMMARYThe small individuals were examined before the height of the breeding season, and there is a probability that many or most of the indeterminate individuals would become male. Hermaphrodite individuals have been observed previously, and in certain samples 10% of the males contain doubtful young ova in the gonad. It is therefore concluded that Patella vulgata is apparently a protandric hermaphrodite, but that the evidence is not yet sufficiently good to prove protandry.It is suggested that possibly two kinds of male, which may be recognisable by chromosome constitution, may occur, one being pure male and one protandric, and also that sex-change may be controlled by as yet unknown metabolic conditions.The breeding period is discussed ; it may extend from August to March at Plymouth in different seasons, and spawning may occur within this period. A maximum of spawning appears to occur about January-February. The conditions controlling breeding and spawning in Patella are unknown, and as the course of seasonal shell-growth is unknown, although shell-growth is general at the end of the breeding season, it is suggested that research on the subjects in the future should be combined.

Seasonal Variations in Fecundity and Egg Size of The Common Goby, Pomatoschistus Microps

1989 ◽  
Vol 69 (3) ◽  
pp. 535-543 ◽  
Author(s):  
S.I. Rogers
Keyword(s):  
Breeding Season ◽  
Adult Life ◽  
Male Fish ◽  
Adult Life Span ◽  
The Common ◽  
Building Activities ◽  
Iteroparous Species ◽  
Sexually Mature ◽  
Brackish Water Fish ◽  
Common Goby

The common goby Pomatoschistus microps (Krøyer), is a small and abundant brackish water fish, which becomes sexually mature after the first winter of life and usually survives for only a single breeding season (Miller, 1975). During a protracted breeding season from approximately mid-April to August or September, the goby can produce up to 9 or 10 separate batches of eggs. It is therefore considered to be an iteroparous species, but because of the short adult life-span during which spawning occurs, this species has been termed an abbreviate iteropare (Miller, 1984). The nest-building activities of the male fish, courtship behaviour and subsequent brood-care are well documented (Vestergaard, 1976).

INFLUENCE OF RESHEARING JUST PRIOR TO BREEDING ON REPRODUCTIVE PERFORMANCE OF A SOUTHDOWN FLOCK SELECTED FOR DATE OF BIRTH

1973 ◽  
Vol 53 (3) ◽  
pp. 399-403
Author(s):  
F. A. THRIFT ◽  
R. H. DUTT
Keyword(s):  
Statistical Model ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Significant Source ◽  
Breeding Period ◽  
Sources Of Variation ◽  
Treatment Interaction

Data involving 130 ewe-yr observations were collected over a 2-yr period from a flock of purebred Southdown sheep that had closed to outside breeding since 1957 and selected for date of birth. Three treatments were imposed on the flock just prior to the breeding season: (1) rams unsheared, ewes unsheared; (2) rams sheared, ewes unsheared; and (3) rams sheared, ewes sheared. All ewes and rams were shorn each year during the 2nd wk of May. The ewes and rams were reshorn according to treatment each year on 28 July and a 120-day breeding period began immediately thereafter. The ewe traits studied were date of first estrus, date of conception, lambing date, lambs born per ewe lambing, and lambs reared per ewe lambing. The data were analyzed using a statistical model that included year, treatment, year by treatment interaction, and sire within year and treatment. Year, treatment, and the year by treatment interaction were all nonsignificant sources of variation influencing the various traits. However, sire to which the ewes were bred was a significant source of variation for date of first estrus, date of conception, lambing date, and lambs born per ewe lambing, but was nonsignificant for lambs reared per ewe lambing.

scholarly journals Masculinization of Banggai Cardinalfish (Pterapogon kauderni) using 17α-Methyltestosterone-enriched Artemia sp.

Omni-Akuatika ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 135
Author(s):  
Muhammad Safir ◽  
Desiana Trisnawati Tobigo ◽  
Seftina F Mangitung ◽  
Madinawati Madinawati ◽  
Zainab Zainab
Keyword(s):  
Survival Rate ◽  
Hormone Treatment ◽  
Male Fish ◽  
Daily Growth ◽  
Randomized Design ◽  
Spawning Cycle ◽  
Male Sex ◽  
Completely Randomized Design ◽  
Central Sulawesi ◽  
Eggs And Larvae

Banggai Cardinalfish (Pterapogon kauderni) is one of the endemic fish from the waters of the Banggai Islands, Central Sulawesi Province. One factor challenging the production of P. kauderni larvae is the male fish will nurture the eggs and larvae for 30 days, hindering next spawning cycle. One effort to overcome this problem an increase of male fish number should be performed, for example through sex reversal. This study aimed to determine the effectiveness of the hormone 17α-methyltestosterone (17α-MT) through Artemia sp. to increase male sex percentage P. kauderni. This study used a completely randomized design by testing four treatments namely feeding Artemia sp. which has been soaked with 2.0 mg of the 17α-MT hormone for two- hours given to P. kauderni larvae for 10 days (A); 20 days (B); 30 days (C), and without hormone treatment 17α-MT (control). Each treatment included control was performed in triplicates. The percentage of male sex was 93.33 % at 30 days treatment and was higher (P<0.05) compared to controls (53.3 %). Additionally, the results showed that daily growth rate, biomass gain and survival rate of all treatments were not significantly different (P>0.05) with those of control. In conclusion, Artemia sp. contained 17α-methyltestosterone enhanced male percentage of P. kaurderni. Keywords: growth, male percentage, Artemia sp., survival rate, Pterapogon kauderni

scholarly journals A multidisciplinary experimental study on the effects of breeders diet on newborn seahorses (Hippocampus guttulatus)

2020 ◽  
Author(s):  
Miquel Planas ◽  
Ike Olivotto ◽  
María Jesús González ◽  
Rosaria Laurá ◽  
Matteo Zarantoniello
Keyword(s):  
Fatty Acid ◽  
Breeding Season ◽  
Nutritional Deficiencies ◽  
Breeding Period ◽  
Fatty Acid Profiles ◽  
High Quality ◽  
Total N ◽  
Morphological Alterations ◽  
Hippocampus Guttulatus ◽  
Income Sources

Abstract The global trade in seahorses is increasing and new rearing techniques are currently available for a few species. One of the main bottlenecks in seahorse production is reproduction success, which is dependent upon the administration of high quality diets to breeders. However, very little is known about the most adequate diets, on how they should be administered and on how they might affect newborn performance. In this study, three homogeneous groups of adult seahorses Hippocampus guttulatus were maintained in captivity. Each group was fed on one of the following diets since the onset of the breeding period: Unenriched adult Artemia (Diet A), unenriched adult Artemia and mysidaceans (Diet AM) and mysidaceans (Diet M). As a positive control we used a wild pregnant male. The mixed diet AM provided the highest overall breeding success and reasonable fatty acid profiles, and better resembled newborn from a wild male. The use of only mysidaceans (Diet M) provided the worse results in spite of the high DHA content. Significant differences were observed in newborn characteristics and fatty acid profiles among dietary groups and along the breeding season, especially in total n-3 HUFA and DHA. Monospecific diets including Artemia or mysidaceans very likely suffered nutritional deficiencies, which were reflected in morphological alterations of the muscle tissue (diet A) or abnormal early mortalities in newborn (diet M). Three progressive stages were identified along the whole breeding period: Initial mixed capital-income period (100 – 120 days since the onset of the breeding period), followed by an inflexion period (short transitional stage - income sources), and finally a long period characterized by the use of income sources and the progressive exhaustion of body reserves. Special attention should be deserved to the progressive changes in fatty acid profiles along the breeding season, resulting in a decrease in newborn performance. Considering the time required for a diet to be reflected in newborn, we recommend Hippocampus guttulatus breeders to be fed on a high quality diet for at least three months prior the breeding period.

Seasonal-Variation in the Ranging Behavior of the Platypus (Ornithorhynchus-Anatinus) on the Goulburn River, Victoria

1995 ◽  
Vol 43 (2) ◽  
pp. 193 ◽  
Author(s):  
N Gust ◽  
K Handasyde
Keyword(s):  
Home Range ◽  
Breeding Season ◽  
Radio Telemetry ◽  
Activity Patterns ◽  
Water Levels ◽  
The Body ◽  
Breeding Period ◽  
Ranging Behavior ◽  
Adult Males ◽  
Temporal Separation

Radio-telemetry was used to study the effects of changing reproductive condition and water levels on the ranging behaviour and activity patterns of adult male platypuses in the Goulburn River, Victoria. Home-range size varied greatly between individuals, from 2 . 45 to 15 . 45 ha, but differences in the body weight of individuals did not account for this variability. There was no correlation between the number of burrows used by males and their body size or home-range length. Changing river levels or the animal's breeding condition did not appear to affect the duration of activity periods, which remained constant throughout the study. All radio-tracked animals foraged in a submerged backwater area during high-water conditions, suggesting that platypuses are opportunistic in their habitat usage and may avoid fast-flowing water if calmer areas are available. Although the home ranges of adult males overlapped extensively during the non-breeding period, there was evidence of spatial separation during the breeding season, when animals occupied separate core areas. In addition there appeared to be some temporal separation between adult males during the breeding season. During this period there was greater variation in the times at which animals emerged from their burrows, and some animals became diurnal.

Effects of nestboxes and males on female song activity in the European starling: an experimental study

Behaviour ◽  
2007 ◽  
Vol 144 (10) ◽  
pp. 1255-1271 ◽  
Author(s):  
Rianne Pinxten ◽  
Denitza Pavlova ◽  
Marcel Eens ◽  
Veerle Darras
Keyword(s):  
Breeding Season ◽  
Social Factors ◽  
European Starling ◽  
Day Length ◽  
Control Group ◽  
Breeding Period ◽  
European Starlings ◽  
Female Song ◽  
Song Rate ◽  
Song Production

AbstractEnvironmental, contextual or social factors influencing song in female songbirds have been little studied. Female European starlings Sturnus vulgaris sing robustly throughout most of the year, except during the breeding season when their song production dramatically decreases. Here we experimentally investigated the effect of the presence of males and/or nestboxes on song production in captive female starlings during the breeding season. Spontaneous song activity of two experimental groups and one control group (housed with nestboxes, but no males) was observed for one month from the end of March onwards. Additionally, we tested whether female song rate is related to oestradiol plasma levels. The experimental results showed that song rate significantly decreased with the progressing of the breeding season and this process seemed not to be regulated by oestradiol. Nestboxes clearly promoted song production, as previously found in male starlings, while the presence of males negatively affected female song rate. Taken together these results indicate that, in the course of the breeding period, the suppressive influence of the day length and the presence of males on female song production override the stimulating effect of nestboxes, and that engagement in breeding activities is largely incompatible with singing in female starlings.

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