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The spawning characteristics of the konoshiro gizzard shad Konosirus punctatus in Tokyo and Sagami Bays, including spawning grounds, periods, water temperature and salinity, and relationship of egg distribution with environmental conditions were studied. Shifts in the main spawning grounds and environmental changes in water temperature and salinity during spawning in each bay were observed. It was found that: (i) the spawning period in both bays was from April to July; (ii) the main spawning peak periods and grounds were May in outer Tokyo Bay, June to July in inner Tokyo Bay, and April in Sagami Bay, off Hayama; (iii) spawning grounds in Tokyo Bay dispersed northward from the outer to the inner bay after May, and in Sagami Bay, westward from Hayama after April; (iv) these shifts correlated with environmental changes, from colder to warmer temperature, from higher to lower salinity, and from heavier to lighter specific gravity; (v) water temperature and salinity for major spawning ranged from 16 to 19°C and 31.5–34.5 p.s.u. with resulting specific gravity of 23.0–25.0 kg/m3. The spawning grounds and periods of this species appeared to be decided by definite spawning temperature and salinity, which are fundamental ecological factors. [ABSTRACT FROM AUTHOR]

From 250 g of carp hepatopancreas, 0.29 mg of the purified enzyme was obtained. The bond specificity of cathepsin S for a -neoendorphin and neurotensin was 6 Arg-7 Lys and 3 Tyr-4 Glu, respectively. The cleavage sites for insulin B-chain were estimated to be the bonds at 3 Asn-4 Gln, 6 Leu-7 Cys, 12 Val-13 Glu, 13 Glu-14 Ala, 16 Tyr-17 Leu, 22 Arg-23 Gly, 24 Phe-25 Phe and 26 Tyr-27 Thr. P2 position on these peptides were bulky and hydrophobic amino acid residues such as Phe or Leu, small amino acid residues such as Gly, Ala and Val were also accepted in these positions. Regarding the protein substrates, cathepsin S degraded carp a -actinin, actin, tropomyosin and troponins T and I although the proteolyzing speeds were distinct from one another. [ABSTRACT FROM AUTHOR]

The effects of nutrient salts eluted from artificial algal reef blocks made with sea-bottom sediment (hedoro) and cement to the growth and survival rate of the gametophytes and juveniles of Eisenia bicyclis were investigated. When each sample block was submerged in filtered seawater for 28 days, the nutrient salt content from the hedoro increased with time and, in particular, the amounts of NO3 -N and NO2 -N reached a constant level on day 10. We observed that the lower the cement ratio, the higher the concentrations of eluted NH4 + -N and PO4 3 -P. The growth of gametophytes as well as juveniles was highest in the elution of the block with the lowest cement ratio of 30%. In con-trast, the survival rate of gametophytes and juveniles decreased linearly with time and the survival rate was higher for the hedoro blocks than for the block made of mortar. [ABSTRACT FROM AUTHOR]