The first report of albinism in a Sundaland endemic rodent

Mammalia ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jonathan A. Nations ◽  
Ahmad Mursyid ◽  
Ryski Darma Busta ◽  
Sah Putra Adrian ◽  
Heru Handika ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Mature Male ◽  
Congenital Disorder ◽  
Domesticated Animals ◽  
First Report ◽  
West Sumatra ◽  
Sexually Mature

AbstractAlbinism, a congenital disorder that results in a lack of melanin deposition, is common in domesticated animals but rare in nature. Among the ∼2500 species of rodents worldwide, only 67 have published reports of albinism. Here we report the capture of an albino murid (Muridae: Rodentia) from Mt. Singgalang in West Sumatra, Indonesia. The specimen is an adolescent but sexually mature male Maxomys hylomyoides, a montane Sumatran endemic. To our knowledge, this specimen represents the first reported albino rodent from Indonesia and Sundaland, and only the second from Southeast Asia.

Exteroceptive Factors, Sexual Maturation and Reproduction in the Female Rat

1979 ◽  
Vol 13 (3) ◽  
pp. 283-286 ◽  
Author(s):  
M. L. Norris ◽  
C. E. Adams
Keyword(s):  
Reproductive Performance ◽  
Sexual Maturation ◽  
Sexual Maturity ◽  
Mature Male ◽  
Female Rat ◽  
Vaginal Opening ◽  
Sexually Mature

Summary Keeping a sexually mature male with a weanling female rat advanced neither the time of vaginal opening nor that of 1st oestrus. In 2 of 3 experiments females kept singly after weaning reached sexual maturity significantly earlier than did grouped females. The reproductive performance of females mated at 1st oestrus was not significantly different from that of older primiparae. 26 rats gave birth to an average of 9·3 young at 59·5 days of age, and 22 of them reared 96% of the young to weaning.

Medullary bone in male budgerigars (Melopsittacus undulatus) with testicular neoplasms

2022 ◽  
pp. 030098582110691
Author(s):  
Nathan K. Hoggard ◽  
Linden E. Craig
Keyword(s):  
Bone Density ◽  
Interstitial Cell ◽  
Egg Laying ◽  
Cell Tumor ◽  
Mature Male ◽  
Testicular Neoplasms ◽  
Testicular Neoplasm ◽  
Medullary Bone ◽  
Sustentacular Cell ◽  
Sexually Mature

Medullary bone is a calcium-rich, labile bone normally occurring in female birds with each egg-laying cycle. The stimulus for formation of medullary bone is, in part, the cyclic increase in serum estrogens produced by preovulatory ovarian follicles. Increased bone density due to formation of medullary bone, particularly in pneumatic bones, has been termed polyostotic hyperostosis, even if physiologic. This study investigated the formation of medullary bone in nonpneumatic (femur) and pneumatic (humerus) bones in sexually mature male budgerigars submitted for autopsy. Of the 21 sexually mature male budgerigars submitted for autopsy, 7 (33%) had medullary bone in 1 or more bones examined. All 7 male budgerigars with medullary bone had a testicular neoplasm, which was morphologically consistent with a testicular sustentacular cell tumor, seminoma, or interstitial cell tumor. Medullary bone was not present in the 14 cases with other diseases. Medullary bone formation in pneumatic and nonpneumatic bones can occur in male budgerigars with testicular neoplasms. Radiographic increases in medullary bone density, particularly in the humerus, could provide antemortem indication of testicular neoplasia in male budgerigars.

scholarly journals Urine from Sexually Mature Intact Male Mice Contributes to Increased Cardiovascular Responses during Free-Roaming and Restrained Conditions

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Dexter L. Lee ◽  
Justin L. Wilson
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Male Mouse ◽  
Cardiovascular Responses ◽  
Mature Male ◽  
Physical Contact ◽  
Male Mice ◽  
Intact Male ◽  
Baseline Values ◽  
Sexually Mature

Pheromones in the urine regulate aggression of male mice and castrated males produce less of these pheromones. We tested the hypothesis that pheromones in the urine of sexually mature-intact (SMI) males placed in the cage bedding of an individually housed male mouse or in a mouse restrainer would contribute to a significant increase in mean arterial pressure (MAP), heart rate (HR), and activity. Sexually mature male C57BL/6 mice were implanted with a biotelemetry transmitter to measure MAP, HR, and activity. Urine (200 μL) from SMI mice placed in the cages of singularly housed male mice caused significant changes above baseline values for MAP (21±4 mmHg), HR (145±25 bpm), and activity (9±2 counts) when compared to urine from castrated mice-induced MAP (11±3 mmHg), HR (70±15 bpm), and activity (5±1 counts). Pretreatment with terazosin significantly reduced the change in MAP (9±3 mmHg), heart rate (90±15 bpm), and activity (4±2 counts) responses to urine from SMI males. Saline did not significantly increase MAP, HR, or activity in any group. During restraint, urine from SMI mice caused a significant change in MAP (5±0.4 mmHg) and HR (17±1 bpm); urine from castrated mice did not cause a significant increase in MAP and HR. Our results demonstrate that a significant increase in MAP, HR, and activity occurs when male mice are exposed to urine pheromones from SMI males. In summary, pheromones in the urine of SMI male excreted in the cage bedding and mouse restrainers contribute to a significant increase in cardiovascular responses in the absence of direct physical contact with a different male mouse or animal handler.

scholarly journals Crocodylian Head Width Allometry and Phylogenetic Prediction of Body Size in Extinct Crocodyliforms

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Haley D O’Brien ◽  
Leigha M Lynch ◽  
Kent A Vliet ◽  
John Brueggen ◽  
Gregory M Erickson ◽  
...  
Keyword(s):  
Body Size ◽  
Fossil Record ◽  
Mature Male ◽  
Head Width ◽  
Hard Tissue ◽  
Broad Array ◽  
Phylogenetic Model ◽  
Highly Correlated ◽  
Sexually Mature ◽  
Size Estimates

Synopsis Body size and body-size shifts broadly impact life-history parameters of all animals, which has made accurate body-size estimates for extinct taxa an important component of understanding their paleobiology. Among extinct crocodylians and their precursors (e.g., suchians), several methods have been developed to predict body size from suites of hard-tissue proxies. Nevertheless, many have limited applications due to the disparity of some major suchian groups and biases in the fossil record. Here, we test the utility of head width (HW) as a broadly applicable body-size estimator in living and fossil suchians. We use a dataset of sexually mature male and female individuals (n = 76) from a comprehensive sample of extant suchian species encompassing nearly all known taxa (n = 22) to develop a Bayesian phylogenetic model for predicting three conventional metrics for size: body mass, snout–vent length, and total length. We then use the model to estimate size parameters for a select series of extinct suchians with known phylogenetic affinity (Montsechosuchus, Diplocynodon, and Sarcosuchus). We then compare our results to sizes reported in the literature to exemplify the utility of our approach for a broad array of fossil suchians. Our results show that HW is highly correlated with all other metrics (all R2≥0.85) and is commensurate with femoral dimensions for its reliably as a body-size predictor. We provide the R code in order to enable other researchers to employ the model in their own research.

scholarly journals Gonadotropin Potency Variation in Anterior Pituitaries from Sexually Mature Male Quail (Coturnix coturnix japonica)

1969 ◽  
Vol 48 (2) ◽  
pp. 718-721 ◽  
Author(s):  
Wayne Bacon ◽  
F.L. Cherms ◽  
Gordon J. Macdonald ◽  
W.H. McShan
Keyword(s):  
Mature Male ◽  
Coturnix Japonica ◽  
Coturnix Coturnix Japonica ◽  
Coturnix Coturnix ◽  
Sexually Mature

Importance of the Variation in Life History Parameters of Atlantic Salmon (Salmo salar)

1985 ◽  
Vol 42 (3) ◽  
pp. 615-618 ◽  
Author(s):  
Richard L. Saunders ◽  
Charles B. Schom
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Population Size ◽  
Salmo Salar ◽  
Great Variability ◽  
Mature Male ◽  
Life History Parameters ◽  
Atlantic Salmon Salmo Salar ◽  
Sexually Mature ◽  
Mature Male Parr

Atlantic salmon (Salmo salar) demonstrate great variability in their life history; individuals from a given year-class can spawn during several years and can, therefore, breed with salmon from other year-classes. Atlantic salmon can mature after 1–4 sea-winters and some males mature as parr, during the second through fifth years, before going to sea. Salmon may survive to spawn more than once; some spawn several times. This variability in life history may be a safeguard against loss of small stocks through several successive years of reproductive failure, since nonspawning individuals in the river or at sea could spawn in subsequent years. Spawning populations are frequently quite small. The effective spawning population size may be potentially much larger, however, since members of several year-classes, including sexually mature male parr and anadromous adults of various ages, contribute to spawning. The level of inbreeding may be relatively low, since a number of year-classes, each with different sets of parents, are represented during spawning.

In vitro suppression of segmentation in Echinococcus multilocularis with morphological transformation of protoscoleces into monozoic adults

Parasitology ◽  
1975 ◽  
Vol 71 (1) ◽  
pp. 125-136 ◽  
Author(s):  
J. D. Smyth ◽  
Zena Davies
Keyword(s):  
Echinococcus Multilocularis ◽  
Cell Lineage ◽  
Somatic Growth ◽  
Mature Male ◽  
Morphological Transformation ◽  
Asymmetric Shape ◽  
Complete Set ◽  
Axenic Conditions ◽  
Sexually Mature

When protoscoleces of Echinococcus multilocularis were cultured in vitro, under axenic conditions in either monophasic or diphasic media, segmentation was suppressed in most organisms, some 70–80% of which developed into unsegmented, monozoic forms with a complete set of sexually mature male and female genitalia. The most striking feature of monozoic worms was the large lateral swelling produced by the cirrus sac the effect being to produce organisms with an unusual asymmetric shape. Worms which did not become monozoic either (a) underwent some somatic growth, developed two sets of genitalia and became ‘pseudosogmented’, i.e. with the inter-proglottid membranes absent or poorly defined, or (b) became vesicular or abnormal. The mechanisms which could be involved in the suppression of somatic growth and the induction of the monozoic condition, are examined in terms of cell lineage. The possible significance of these results in understanding the evolution of the cestodes is discussed.

The Effect of Impoundment on the Population and Movement of Atlantic Salmon in Ellerslie Brook, Prince Edward Island

1960 ◽  
Vol 17 (4) ◽  
pp. 453-473 ◽  
Author(s):  
J. W. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Prince Edward Island ◽  
Salt Water ◽  
Mature Male ◽  
Freshwater Discharge ◽  
Age Group ◽  
Annual Variations ◽  
Sexually Mature ◽  
Mature Male Parr

During autumn spates Atlantic salmon (Salmo salar) commonly enter the small spring-fed streams of Prince Edward Island and spawn. Annual variations in freshwater discharge from Ellerslie Brook were found to determine the number of salmon and time of ascent. A pond formed on the brook created a habitat that exercised a strong retaining influence on the movements of spawners, kelts, parr, and migrating smolts. Smolts which stayed in the pond suffered heavy mortalities.Movements by sexually mature male parr, within and between fresh and salt water, occurred in the fall. Some parr remained in the estuary (0–27‰ salinity) throughout the year. The pond provided a habitat for parr.Smolt transformation at ages II and III occurred in the stream, pond, and estuary in the spring. Pond and stream smolts of the same age group were similar in size when they migrated.

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