Up to the present day, the affinities of Döderleinia berycoides (HILGENDORF) are not certainly known. In this anatomical study it was found that this species was closely related to Synagrops japonicus (STEINDACHNER et DÖDERLEIN). It is worthy of a special mention that it is characteristic of these species to have a spherical hollow on each siele in the basioccipital and the exoccipital of the ventral side of the cranium, which the writer herein calls the basicccipital fossa, and in which the anterior spherical branch of the air-bladder firmly fits. In spite of the resemblance of Synagrops to Apogon (A pogonidae) in having the seperated dorsals and two spines in anal fin, the affinity of this genus seems rather closer to Döderleinia. It should be transferred to the Serranidae and included in the Doderleininae with the latter. On the other hand, these genera are related to Stereolepis, Malakichtliys (Serranidae), and Acropoma (Acropomidae) in some important features.
To increase the production of “Ayu” Plecoglossus allivelis (T. & S.), it is necessary to catch the young in abundance near coasts or at estwaries of rivers and release them in rivers. The author studied on the relations between the number of the anadromous “ayu” and the water-temperature, weather, and season. The following results were obtained: 1) The anadromous period is from early April to early June, the water-temperature during the period ranging from 13.0 to 16.0°C. 2) The maximum number of anadromous young “Ayu” is seen at 9-10 A. M. or 1-3 P. M., then follows a decrease. In midnight they also enter rivers, but their number is very small compared with that of the midday. 3) The number of the anadromous “ayu” increases suddenly a few days before bad weather, rainfall or flood.
The present article contains descriptions of life colors of rare 18 species . Amongthem are the following species in perishable natural colors which seem not to havehitherto been recorded: Harpodon microchir; Lestidium jaPonicum; young of Epinephelus caeruleopunctatus; young of Duymaeria flagellifera; Lactophrys concatenatus and Ostracion fornasini.
The experiment was undertaken so as to see that the size of fishing hook and the skill of angler might have effect to the average size of fish caught, Acanthogobius flavirnanus, a common game fish in Tokyo Bay. The two sizes of hook for this bait fishing (Fig. 1) are used by twelve anglers, which can be classified to the three degrees of skill, (expert, middle class and beginners) the according to their careers in sports fishing. All the anglers, on the same boat, fished at same fishing ground, where supposed to have the same group of fish, having the same size composition. The size of fish caught by them was measured, and the figures were examined by statistical method. As it is clear even in the graphs and the table of size distribution of fish caught, the remarkable differences of average size were found by the difference of size of hook used (Fig. 2). And by the degree of skill of anglers some difference of average size of fish caught was recognized between experts and others (Fig. 3).