Nakao k (7 resultados)

SC. Condición: Gut. Obr., [WES1].// Deu 400g.

Soft cover. Condición: Very Good. - 195 mm. Soft cover (textured lilac plastic) with gilt titling to front and spine. Illustrated. Pp. [16], 1917. India paper. Mild wear and rubbing to cover. Former owner's address sticker affixed to title page with ink impression on facing page. Very little wear. Nice handy volume. Overall, VGC. …

The effects of imposex and parasite infection on the reproductive cycle of Neptunea arthritica as well as sexual maturity size were examined from April 2003 to August 2004 in Saroma Lagoon, Hokkaido, Japan. Samples were sexed and divided into two groups (normal and abnormal), based on the degree of imposex and parasite infection. In normal whelks, males reached sexual maturity at a smaller size (60 mm in shell length) than females (75 mm). Normal whelks copulated from March to August, with a peak between May and July, and spawned from May to August, with a peak in June?July. In all groups, the female ovary and pallial oviduct, and the male seminal vesicle developed synchronously, and inverse to the male testis. Abnormal whelks follow a normal reproductive cycle. However, significantly lower reproductive organ index values, modifications in the number of individuals and periods extension in each developmental stage were observed. Gonads of individuals with severe imposex (stage 3) and parasite infection were reduced to a thin layer of tissue or eliminated. Imposex (stage 3) and parasite infection had serious effects on the population reproductive cycle of N. arthritica, but infection by parasites seemed to be the more disruptive phenomenon according to its proportion (25%). 10 pp., 8 figs, 4.…

The age and growth of the whelk, Neptunea arthritica, was estimated based on growth striae on the operculum. Individual whelks were sexed and divided into normal and abnormal groups, based on the presence of imposex and parasite infection. The monthly marginal growth was used to determine the annual growth mark formation on the operculum. The whelk s sex (male and female), condition (normal and abnormal) and size (mature and immature) were evaluated as factors that can affect the marginal growth. Only in normal females did size affect the marginal growth, suggesting that parasite infection and imposex were not a biasing factor in the age estimation. Significant differences between low and high monthly marginal growth in normal males were found. Between operculum length and shell length and total body weight a positive relationship was found, while the same trend was observed in all female groups as well as abnormal males, but differences were not significant. The same relationship was observed between the number of stria with shell length and total body weight in all groups. The results suggest that opercula striae could be used to age N. arthritica. The Gompertz equation was the best curve that fitted the data for growth in normal groups, based on Akaike s information criteria, and it was used for all groups. The age at first sexual maturity was estimated for normal males and females to be 4.6 and 6.1 years, respectively. 12 pp., 8 figs, 4.…

Softcover. Condición: Near Fine. 187 pages in near fine condition. Text is in JAPANESE. Japanese title reads "NIHON NO SHARYOU Style Book" (Japanese Railroad Car Style Book). Pages are clean and unmarked, filled with beautiful b&w technical illustrations of various japanese trains. Includes statistics, plans, and descriptions. Bound in black, blue, white and yellow card covers with french flaps. Light wear around the edges. SCARCE. NF Size: 12 x 8 1/2. Nakao, Y. (ilustrador). Book.…

Condición: Fine. The book is in fine condition.

Condición: Fine. Number of books: 8.