Thyroid hormone dynamics during the nursing period in harbour seals, Phoca vitulina

1998 ◽  
Vol 76 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Martin Haulena ◽  
David J Aubin ◽  
Padraig J Duignan
Keyword(s):  
Thyroid Hormones ◽  
Post Partum ◽  
Phoca Vitulina ◽  
Postnatal Period ◽  
Lactation Period ◽  
Harbour Seals ◽  
Total Thyroxine ◽  
Phocid Seals ◽  
Free Ranging ◽  
Circulating Levels

The postnatal period in phocid seals is metabolically demanding, requiring mobilization of maternal energy stores, which are then transferred via the milk for subsequent deposition in the pup. Thyroid hormones may be important modulators of these processes, and so we monitored circulating levels of free and total thyroxine (T4), triiodothyronine (T3), and reverse T3 (rT3) in 13 free-ranging female harbour seals (Phoca vitulina) and their pups for up to 25 days post partum. Early total and free T4 levels, percentage of free T4, total and free T3 levels, rT3 levels, and rT3:T3 ratios were significantly higher in pups than in mothers. Total and free T4 levels, percentage of free T4, free T3 and rT3, levels, and rT3:T3 ratios in pups decreased significantly over the lactation period, while maternal total and free T4 levels increased significantly. Our findings highlight the dynamic nature of thyroid hormones and their involvement in regulating metabolism throughout this important period. This is the first report examining free T3 and rT3 levels in phocid seals.

scholarly journals PCB-Related Alteration of Thyroid Hormones and Thyroid Hormone ReceptorGene Expression in Free-Ranging Harbor Seals (Phoca vitulina)

2006 ◽  
Vol 114 (7) ◽  
pp. 1024-1031 ◽  
Author(s):  
Maki Tabuchi ◽  
Nik Veldhoen ◽  
Neil Dangerfield ◽  
Steven Jeffries ◽  
Caren C. Helbing ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Phoca Vitulina ◽  
Harbor Seals ◽  
Free Ranging

scholarly journals Aerial low-frequency hearing in captive and free-ranging harbour seals (Phoca vitulina) measured using auditory brainstem responses

2016 ◽  
Vol 202 (12) ◽  
pp. 859-868 ◽  
Author(s):  
Klaus Lucke ◽  
Gordon D. Hastie ◽  
Kerstin Ternes ◽  
Bernie McConnell ◽  
Simon Moss ◽  
...  
Keyword(s):  
Low Frequency ◽  
Auditory Brainstem ◽  
Phoca Vitulina ◽  
Auditory Brainstem Responses ◽  
Harbour Seals ◽  
Free Ranging

Changes in food intake, mass, and fat accumulation in association with variations in thyroid hormone levels of harbour seals (Phoca vitulina)

1991 ◽  
Vol 69 (9) ◽  
pp. 2470-2479 ◽  
Author(s):  
Deane Renouf ◽  
Elizabeth Noseworthy
Keyword(s):  
Locomotor Activity ◽  
Food Intake ◽  
Thyroid Hormones ◽  
Water Temperature ◽  
Cooling Water ◽  
Phoca Vitulina ◽  
Harbour Seals ◽  
Direct Association ◽  
Thyroid Hormone Levels ◽  
Mass Accumulation

Food intake, mass, fat, locomotor activity, and thyroid hormones were monitored in five captive harbour seals (Phoca vitulina) over an 18-month period. Food intake ranged from anorexia to 11% body weight, with changes in body mass reaching 59% in the males. Food intake was negatively related to changes in mass and blubber except during a 6-week period in the fall when the three variables were positively correlated. From the end of November until June, when food intake decreased progressively, mass and fat increased, but not in what was otherwise direct association. Changes in fat were more consistently negatively related to water temperature than were changes in mass. When the male seals were losing weight despite rising food consumption, free thyroxine (T4) levels were positively correlated with food intake and water temperature but negatively correlated with mass and fat changes; the reverse relationships held for ratios of tri-iodothyronine (T3) to free T4. Over the winter months, when mass and blubber were augmenting despite lowered food intake, free T4 levels were significantly lower, whereas T3 and its ratio to both free and total T4 were reduced when food intake and mass accumulation were directly related. In the female seal, these hormones were not clearly associated with any of the variables measured. Locomotor activity was positively related to food intake but not in any clear way to levels of thyroid hormones. These results are discussed in the context of the metabolic defense of fat levels for insulation in cooling water.

scholarly journals Relationships between in vitro lymphoproliferative responses and levels of contaminants in blood of free-ranging adult harbour seals (Phoca vitulina) from the North Sea

2013 ◽  
Vol 142-143 ◽  
pp. 210-220 ◽  
Author(s):  
Aurélie Dupont ◽  
Ursula Siebert ◽  
Adrian Covaci ◽  
Liesbeth Weijs ◽  
Gauthier Eppe ◽  
...  
Keyword(s):  
North Sea ◽  
Phoca Vitulina ◽  
The North ◽  
Harbour Seals ◽  
The North Sea ◽  
Free Ranging

Thyroid hormones (th) and 5'-monodeiodinase (5'-md) activity in goat's milk from the early, mid- and late lactation period

2004 ◽  
Vol 52 (3) ◽  
pp. 349-359 ◽  
Author(s):  
A. B. Ślebodziński ◽  
J. Twardon
Keyword(s):  
Thyroid Hormones ◽  
Post Partum ◽  
Active Form ◽  
Physiological Role ◽  
Postnatal Life ◽  
Standard Diet ◽  
Lactation Period ◽  
Early Lactation ◽  
Highly Active ◽  
Lactation Phase

The physiological significance of thyroid hormones (TH) present in colostrum and milk is still under consideration. The present study was aimed at determining milk thyroxine (T4) and triiodothyronine (T3) levels in three lactation phases (early, mid- and late) of the goat, and to measure activity of the milk 5'-deiodinase (5'-MD) enzyme responsible for the intramammary conversion of pro-hormone T4 to its metabolically highly active form T3. Thirty-two milk goats (Polish White breed) fed a standard diet were used for milk sampling. The highest TH levels in mammary secretion were recorded during the first 2-3 days post partum. Then the hormone levels decreased, and by about Day 7 fluctuated around the overall mean for the early-lactation phase (Days 1 to 24 of lactation), recording 0.134 ± 0.059 µg T4 and 150.8 ± 2.80 ng T3 in 100 ml of the milk. Such T4 concentrations appeared to be comparable to those in the rabbit and human, whereas the concentration of T3 was higher than in the cow, pig and mare's milk. Milk 5'-MD activity was higher (P < 0.01) during early and late lactation, compared to the mid-lactation phase. It coincided with low T4 and high T3 milk levels during early lactation, and with high milk T4 and low T3 concentrations during late lactation. The quantity of T4 and T3 available to newborn kids in milk suggests that TH ingested with the colostrum may have a physiological role during the early postnatal life of suckling goats.

scholarly journals Campylobacter pinnipediorum subsp. caledonicus and C. pinnipediorum subsp. pinnipediorum recovered from abscesses in pinnipeds

2020 ◽  
Vol 142 ◽  
pp. 41-46
Author(s):  
G Foster ◽  
JL Baily ◽  
F Howie ◽  
AC Brownlow ◽  
JA Wagenaar ◽  
...  
Keyword(s):  
Bacterial Isolate ◽  
Novel Species ◽  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
The Novel ◽  
California Sea Lions ◽  
Sea Lions ◽  
Harbour Seals ◽  
Phocid Seals ◽  
Bite Wounds

Campylobacter pinnipediorum was described recently for isolates recovered from pinnipeds. The novel species was further split into 2 subspecies based on host and geography, with C. pinnipediorum subsp. pinnipediorum recovered from otariid seals in California (USA) and C. pinnipediorum subsp. caledonicus recovered from phocid seals in Scotland. We report details of the infections of 7 pinnipeds from which C. pinnipediorum was isolated: C. pinnipediorum subsp. caledonicus was isolated from 2 harbour seals Phoca vitulina and a single grey seal Halichoerus grypus, and C. pinnipediorum subsp. pinnipediorum was isolated from California sea lions Zalophus californianus. Six of the isolates were recovered from samples collected at post-mortem investigation. In 2 of the Scottish seals and in 3 of the California seals, C. pinnipediorum was the sole bacterial isolate recovered from abscesses present and suggests they may have resulted from conspecific or intraspecific bite wounds.

Description of the Pregnancies, Labours, and Pre- and Post-Partum Events of Two Harbour Seals (Phoca vitulina) in a Zoological Environment

2006 ◽  
Vol 32 (2) ◽  
pp. 145-151 ◽  
Author(s):  
Marie-Anne Blanchet ◽  
Genevieve Desportes ◽  
Tiffany Nance ◽  
Cecilia Vanman
Keyword(s):  
Post Partum ◽  
Phoca Vitulina ◽  
Harbour Seals

Testing predictions of optimal diving theory using animal-borne video from harbour seals (Phoca vitulina concolor)

2014 ◽  
Vol 92 (4) ◽  
pp. 309-318 ◽  
Author(s):  
Susan G. Heaslip ◽  
W. Don Bowen ◽  
Sara J. Iverson
Keyword(s):  
Nova Scotia ◽  
Temporal Pattern ◽  
Dive Depth ◽  
Dive Duration ◽  
Phoca Vitulina ◽  
Encounter Rate ◽  
Harbour Seals ◽  
Wide Range ◽  
Oxygen Stores ◽  
Free Ranging

Optimal diving theory predicts that animals make decisions that maximize their foraging profitability subject to the constraint of oxygen stores. We examined the temporal pattern of prey encounters within a dive from concurrently collected dive data and animal-borne video from a free-ranging pinniped to test predictions of optimal diving theory. Crittercams were deployed on 32 adult male harbour seals (Phoca vitulina concolor De Kay, 1842) at Sable Island, Nova Scotia, Canada, for 3 days each. Deployments resulted in approximately 3 h of video per seal and a total of 2275 capture attempts for 1474 prey encounter events recorded. We found support for seven of the nine selected predictions of optimal diving theory. As predicted, prey encounters increased with bottom duration; dive duration increased with dive depth; and travel duration, bottom duration, and percent bottom duration decreased over a wide range of travel durations. Descent duration did increase with dive depth, and seals terminated dives earlier when no prey were encountered and when prey were encountered later in a dive. Contrary to prediction, bottom duration did not increase and then decrease for short travel durations and dives were not terminated earlier when travel durations were short and prey encounter rate was low.

Diving behaviour of lactating harbour seals and their pups during maternal foraging trips

1999 ◽  
Vol 77 (6) ◽  
pp. 978-988 ◽  
Author(s):  
W D Bowen ◽  
D J Boness ◽  
S J Iverson
Keyword(s):  
Nova Scotia ◽  
Post Partum ◽  
Dive Duration ◽  
Phoca Vitulina ◽  
Diving Behaviour ◽  
Early Lactation ◽  
Adult Females ◽  
Harbour Seals ◽  
Lactating Females

Female harbour seals (Phoca vitulina) undertake foraging trips during mid to late lactation. We show that they are accompanied by their pup during many of these foraging trips. Time-depth recorder data were obtained from 20 lactating females and 14 of their pups in 1995 and 1996 at Sable Island, Nova Scotia. Overall, females spent 55.4 ± 4.68% (mean ± SE) of their time at sea compared with 39.8 ± 2.29% for pups. Like those of their mothers, pups' dives occurred in clusters or bouts: 71.4 ± 4.4 dives, 2.5 ± 0.15 h in duration. Bouts of diving by females and pups began 0-3 days post partum. Mean dive duration of pups increased from about 1 to 1.5 min over the course of lactation, but was still shorter than that of adult females (1.5-2.25 min). Both females and pups appeared to dive within their theoretical aerobic dive limits (TADL) of 8.9 and 2.6-3.1 min, respectively. Up to 3.6% of dives by some pups may have exceeded their TADL. Pups appeared to compensate for their lesser diving ability by making more and shorter dives per bout than females, particularly during early lactation.

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