The Parathyroid Glands of Two Species of Dolphin—Risso's Dolphin,Grampus griseus,and Bottlenose Dolphin,Tursiops truncatus

Hayakawa, Daisuke; Chen, Huayue; Emura, S.; Tamada, Akira; Yamahira, Tomo; Terasawa, K; Isono, Hideo; Shoumura, Shízuko

doi:10.1006/gcen.1997.7050

Cited by 6 publications

(1 citation statement)

References 20 publications

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“…That of the pig has two lobes [17], and its isthmus is well-developed and pyramidal in shape [7]. On the other hand, the thyroid gland of Risso's dolphin was devoid of the isthmus.…”

Section: Discussionmentioning

confidence: 99%

A Morphological Study of the Thyroid Gland in Risso's Dolphin, Grampus griseus.

Shimokawa

Nakanishi

Hondo

et al. 2002

The Journal of Veterinary Medical Science

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ABSTRACT. To accumulate histological information of cetaceans and basic information about metabolic systems of marine mammals, the thyroid gland of Risso's dolphins was examined by gross anatomical and light and electron microscopic observations. Gross anatomically, right and left lobes of the thyroid were not clearly discriminated, and no isthmus was observed. By light microscopy, irregular or oval follicular lumens were seen, and surrounded by follicular epithelial cells. By electron microscopy, the rough endoplasmic reticulum (rER) was seen adjacently to mitochondria at the basal and lateral regions of the follicular epithelial cells. RERs at the basal side of the cells sometimes contained flocculent material with the same electron density as the follicular lumen component. Microvilli were poorly developed at the apical surface of the cells. In the apical regions of the cells, there were typical Golgi complexes, multivesicular bodies, and granules with various size and electron density. The parafollicular cells were recognized among the follicular epithelial cells and in the interstitial regions but never protruded into the follicular lumen. These cells were present singly and/or formed clusters among the follicular epithelial cells, and often located adjacent to capillaries. They were obviously discriminated from follicular epithelial cells by higher electron density of their granules. In their cytoplasm, well-developed rERs, primary lysosomes, secondary lysosomes, multivesicular bodies, and phagosomes were recognized.

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“…That of the pig has two lobes [17], and its isthmus is well-developed and pyramidal in shape [7]. On the other hand, the thyroid gland of Risso's dolphin was devoid of the isthmus.…”

Section: Discussionmentioning

confidence: 99%

A Morphological Study of the Thyroid Gland in Risso's Dolphin, Grampus griseus.

Shimokawa

Nakanishi

Hondo

et al. 2002

The Journal of Veterinary Medical Science

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Bone density of the arm and forearm as an age indicator in specimens of stranded striped dolphins (stenella coeruleoalba)

et al. 2002

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The age of odontocetes living in the wild is determined mainly by analysis of dentine layers in sections of the teeth. We examined a series of specimens from striped dolphins (Stenella coeruleoalba, Meyen, 1833) that had stranded along the Italian coast of the Mediterranean sea. The present study analyzes and describes bone density in the arm and forearm of the stranded specimens, and correlates the data with total body length of the animal and age as determined by the number of dentine layers in sections of the teeth. According to our model, age can be predicted on the basis of bone density and total body length of the stranded animal. This is the first study to use bone density as a biological parameter to understand the wear and tear of life in the sea. The results suggest that bone density is a new tool for recording age in wild odontocetes. Anat Rec 267: 225-230, 2002.

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