Age and growth of alfonsino Beryx splendens (Lowe) were studied using counts of presumed daily incremental growth rings on the transverse section of otoliths of fish collected from the Kanto District, central Japan. Microstructural growth increments were observed from the core to the outermost margin of the broadest of approximately 50 branches formed on the surface of an otolith. Of 98 otoliths examined, 46 were readable. The number of increments and fish lengths ranged from 448 (218 mm fork length [FL]) to 3701 (411 mm FL). The ages of these fish were estimated to be 1 year, 2 months and 10 years, 2 months, respectively, assuming that an increment was formed daily. The von Bertalanffy growth equation combined for males and females was expressed as follows:where L t is fork length (mm) at yearly age t . The results of the present study were compared with those of other researchers who had studied alfonsino from central Japan.

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Product developers have used a lot of polygon data, approximated from 3D-CAD data, as a collaboration tool on the Internet. It is difficult to deal with this data for example with respect to transmission, computational cost, or rendering, so simplification algorithms are required for data compression. In general, a vertex-clustering algorithm in simplification algorithms is very fast, although it has the problem that topology information is not preserved and for some applications, such as 3D-CAD, it is important to preserve topology information. We define topology information in this paper as genus on the polyhedron and 2-manifold. In this paper, we propose a topology-preserving simplification method using a depthfirst search tree on a vertex-clustering algorithm. Our method does not lose the advantage that vertex-clustering algorithms are fast yet it solves the problem of lost topology information. Experimental results show that this method is effective and is easily adapted to space division algorithms of other vertex-clustering algorithms

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