SUMMARY: A total of 325 pueruli of the spiny lobster Panulirus japonicus was successfully reared in the laboratory at Minami‐Iku Station of Japan Sea‐Farming Association, Shizuoka, Japan, during 1989–1997. Of these pueruli, 136 individuals metamorphosed into the first juvenile stage. The duration of the phyllosoma stage ranged from 231 to 417 days (mean 319.4 days), and it has a tendency to extend as the increase of water volume in the rearing tanks. The number of molting in the phyllosoma stage was 20–31. The body length of the last‐stage phyllosoma ranged from 27.9 to 34.2 mm and the duration of the last stage was 11–26 days. The carapace length of the puerulus stage was 6.0–8.0 mm and the duration was 9–26 days. The present data and those of previous studies suggest that the body size and the duration of phyllosoma stage in captivity are affected by environment as in the field. The duration of the puerulus stage is considered to be controlled basically by water temperature and nutritional conditions in the phyllosoma.

This study examined the capacity of Japanese spiny lobster Panulirus japonicus phyllosoma larvae to absorb nutrients directly from the surrounding water. For this purpose, 48-, 81-, 124-, 160-, and 264-day-old intermoult larvae were starved for 48 h, held for 30 min to 4 h in 0.05 g L ±1 solutions or dispersions of cholesterol, peanut oil, saccharose and horseradish peroxidase in seawater, and subsequently examined by histological and ultrastructural methods. Lipids, carbohydrate, and protein were detected in either the lumen of the midgut gland tubules, the midgut gland cells, the haemolymph or in the cells of the epidermis of all larvae examined after each experimental period, with general improvement of the cell and tissue characteristics over unfed controls. The lipids were also found in the cuticle. Thus, the results provide evidence of nutrient absorption via the digestive tract, and possibly also via the integument. Structural adaptations that may be involved in the process of absorption were tentatively identi®ed. Our observations suggest the possibility that particulate organic matter (POM) and dissolved organic matter (DOM) can be utilized by the P. japonicus phyllosoma larvae, perhaps as supplementary sources of nutrients to macroscopic diets. KEY WORDS

-1). Thus, the results of this study provide clear confirmation that, in addition to the known mode of oral feeding on macroscopic food masses, P. japonicus phyllosoma larvae are also able to absorb nutrients directly from the surrounding medium.

Mass seed production depends a great deal on the development of adequate artificial diets, which in turn depends on the development of methods to speedily and reliably assess the nutritional value of experimental diets. This study examined the sensitivity of light histological and ultrastructural criteria to detect differences in the nutritional value of diets for the Japanese spiny lobster, Panulirus japonicus (V. Siebold), phyllosoma larvae. The acceptability of diets, the apparent absorption of lipids and carbohydrates by the midgut gland cells, and the characteristics of various cell types were determined in 43‐, 106‐ and 143‐day‐old intermoult phyllosoma fed diets of Mytilus edulis (L.) ovary alone (MO) or in combination with Anemia (MO+AR), which so far have given the best results in terms of growth and percentage of metamorphosis into puerulus, and two other diets considered less efficient, viz. Mytilus edulis testis (MT) and Artemia (AR). Acceptability of all diets attained 100% within 10 min of feeding as revealed by observation through the semitransparent cuticle of the larvae. Histological examination of larvae that ingested comparable amounts of food revealed pronounced variation in the absorption of lipids and carbohydrates by the midgut gland cells (AR

Fishing grounds and caught species are diverse in the inland fishing grounds of Japan, and so the business environment of Japanese inland fishery cooperatives (JIFCs) is also expected to be diverse. Based on the fiscal 2017 business reports of JIFCs, this study classified JIFCs into seven types and analyzed differences in the soundness of management and expenditure structure by type. The results showed that, although management in all types of cooperatives exhibited high safety, safety was maintained on the sacrifice of wages and labor costs. These results suggest that the scale of income and expenditure must be expanded, and that the profit margins of stocking ayu and stream dwelling salmonids must be improved.