scholarly journals Degeneration of the olfactory epithelium in the Anguilid eels by hormone treatment

2019 ◽  
Vol 3 (2) ◽  
pp. 48-51
Author(s):  
Ching Fui Fui ◽  
Gunzo Kawamura ◽  
Kazuhiko Anraku ◽  
Bensan Ali ◽  
Nabilah Zieha Sikh Mohamad ◽  
...  
Keyword(s):  
Sexual Maturation ◽  
Side Effect ◽  
Hormone Treatment ◽  
Japanese Eel ◽  
Silver Eels ◽  
Olfactory Cells ◽  
Mucus Cells ◽  
Olfactory Cue ◽  
Olfactory Rosette ◽  
Tropical Eels

While the olfactory cue hypothesis has been proposed for spawning migration of silver eels, it has been shown that olfactory cells and associated mucus cells degenerate in male and female eels after hormonally induced sexual maturation. However, the degeneration of the olfactory organ could be a real event in the sequence of maturation, or may be an unnatural side effect of the hormone treatment itself. We morphologically and histologically examined the olfactory rosettes of hormone-untreated and hormone-treated (mixture of hCG and PG) giant mottled eel (Anguilla marmorata) and Japanese eel (A. japonica). The olfactory rosette from all the hormone-treated specimens significantly degenerated at various degeneration levels even in sexually immature specimens, indicating the side effect of the hormone-treatment. However, a sexually immature non-hormone treated female A. marmorata (87.4 cm TL, 199.4 g BW, at less advanced maturity) had slightly degenerated olfactory rosette. Further studies should focus on conducting natural degeneration of the olfactory rosette during the sexual maturation in tropical eels.

Morphological alteration in two types of gill chloride cells in Japanese eels (Anguilla japonica) during catadromous migration

1998 ◽  
Vol 76 (8) ◽  
pp. 1480-1487 ◽  
Author(s):  
Seiji Sasai ◽  
Toyoji Kaneko ◽  
Sanae Hasegawa ◽  
Katsumi Tsukamoto
Keyword(s):  
Atpase Activity ◽  
Anguilla Japonica ◽  
Japanese Eel ◽  
Morphological Alteration ◽  
Immunocytochemical Staining ◽  
Chloride Cells ◽  
Apparent Difference ◽  
Silver Eels ◽  
Different Types ◽  
Yellow Eels

Gill chloride cell morphology and Na+,K+-ATPase activity were examined in cultured Japanese eels (Anguilla japonica) acclimated to fresh water (FW) or seawater (SW), and in yellow and silver eels caught in wild stocks. Gill Na+,K+-ATPase activity was higher in SW-acclimated cultured eels than in FW eels. Chloride cells were detected in both filament and lamellar epithelia by immunocytochemical staining using anti-Na+,K+-ATPase serum. The filament chloride cells were more abundant and larger in SW eels than in FW eels, whereas there was no apparent difference in lamellar chloride cells. In wild-caught eels, gill Na+,K+-ATPase activity increased as they developed from yellow to silver eels. Filament chloride cells in silver eels were more active than those in yellow eels. In contrast, lamellar chloride cells, which were frequently observed in yellow eels, had decreased in number or disappeared in silver eels. These findings suggest that chloride cells in the filament are responsible for excretion of excess salt in hyperosmotic environments, and that lamellar chloride cells may play a significant role in hypoosmotic environments, presumably acting as sites of ion uptake. The excellent euryhalinity of the Japanese eel may be due, at least in part, to the presence of functionally different types of chloride cells. The activation of filament chloride cells in silver eels in FW, together with the increase in Na+,K+-ATPase activity, could be interpreted as a preadaptive response to forthcoming entry into SW.

Molecular cloning of fresh water and deep-sea rod opsin genes from Japanese eel Anguilla japonica and expressional analyses during sexual maturation 1

FEBS Letters ◽  
2000 ◽  
Vol 469 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Huan Zhang ◽  
Kunihiko Futami ◽  
Noriyuki Horie ◽  
Akihiro Okamura ◽  
Tomoko Utoh ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Fresh Water ◽  
Sexual Maturation ◽  
Deep Sea ◽  
Anguilla Japonica ◽  
Japanese Eel ◽  
Opsin Genes

Ultrastructure of the oocytes of the Japanese eel Anguilla japonica during artificially induced sexual maturation

2001 ◽  
Vol 67 (5) ◽  
pp. 870-879 ◽  
Author(s):  
Takaaki Kayaba ◽  
Noriko Takeda ◽  
Shinji Adachi ◽  
Kohei Yamauchi
Keyword(s):  
Sexual Maturation ◽  
Anguilla Japonica ◽  
Japanese Eel

Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements

2012 ◽  
Vol 103 (1) ◽  
pp. 1-13 ◽  
Author(s):  
M.C. Liendo ◽  
F. Devescovi ◽  
G.E. Bachmann ◽  
M.E. Utgés ◽  
S. Abraham ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Sexual Maturation ◽  
Protein Intake ◽  
Adult Stage ◽  
Fruit Fly ◽  
Hormone Treatment ◽  
Protein Supplements ◽  
Mating Competitiveness ◽  
Anastrepha Fraterculus ◽  
Sexual Signalling

AbstractSexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competitiveness of sterile laboratory males and females that were treated with methoprene (either the pupal or adult stage) and were kept under different regimes of adult food, which varied in the protein source and the sugar:protein ratio. Experiments were carried out under semi-natural conditions, where laboratory flies competed over copulations with sexually mature wild flies. Sterile, methoprene-treated males that reached sexual maturity earlier (six days old), displayed the same lekking behaviour, attractiveness to females and mating competitiveness as mature wild males. This effect depended on protein intake. Diets containing sugar and hydrolyzed yeast allowed sterile males to compete with wild males (even at a low concentration of protein), while brewer´s yeast failed to do so even at a higher concentration. Sugar only fed males were unable to achieve significant numbers of copulations. Methoprene did not increase the readiness to mate of six-day-old sterile females. Long pre-copulatory periods create an additional cost to the management of fruit fly pests through the sterile insect technique (SIT). Our findings suggest that methoprene treatment will increase SIT effectiveness against A. fraterculus when coupled with a diet fortified with protein. Additionally, methoprene acts as a physiological sexing method, allowing the release of mature males and immature females and hence increasing SIT efficiency.

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