Acanthogobius flavimanus (TEMMINCK et SCHLEGEL) is one of the most common and commercially important goby, abundantly found in the bays and estuaries of Japan throughout (Fig.1). The spawning-season extends from January to March in Kyushu. The breeding-room, somewhat flat Y-shaped, is constructed vertically in the tidal flat deposit and with two entrances (Fig.2, A-C: Fig.3). The spawned eggs were attached to the wall of the upper part of this room. The egg is club-shaped, measuring about 5.5mm in length and 0.95mm in width, with adhesive filaments around the basal end (Fig.4). The incubation-period extends about 28 days at the temperature about 13°C. The newly hatched larva is about 4.6mm in total length. The larvae, 4.9-12.0mm in total length, were found to carry a pelagic life in the bay. The young, 15-20mm in total length, were obtained from the bottom of estuaries. Their allimentary tracts contained planktonic copepods (Fig.5). A couple of mature fish were kept in an earthen pipe which was expected to be used as a breeding-room. In each pectoral muscle of both of those parent fish were planted an anterior lobe of the hypophysis of the frog, Rana catesbiana SHAW. Six days after the operation spawned eggs were found attached to the inner wall of the pipe (Fig.2, D-F).
In the present paper the writer gave a detail of the osteological study on the axial skeleton, especially on the cranium and the vertebral column, of the mature Japanese mugilid fish from Kabashima, Nagasaki Pref. By this study the writer found the identity of this sample with Mugil cephalus LINNE and considered that this species is identical with Mugil japonicus described by Von SIEBOLD as to the sample collected from Nagasaki. Lately BOESEMAN revised fishes collected by SIEBOLD and the sample named as Mugil japonicus was identified by him as Mugil cephalus. Ovarian weight of the mature mullet averaged 350-400g and the female fish of this species were always longer than 45cm in body length, whereas the body length of the male fish were invariably less than 40cm. The relationship between the body-length (L) and the body-weight (W) is given by W=0.02817 L2.9755 The appearance of the mullet in the waters off Kabashima and vortices movements of Tsushima currents are intimately connected. In the additional notes the writer dealt with the intestinal convolution of the three species of the two genera, Mugil and Liza, of the Mugilidae. The intestinal convolution of Mugil cephalus (A) is the most complicated of the three and the covolut ion of Liza carinata (C) is simpler than that of Liza haematocheila (B).
The study was carried out concerning the morphological and cytochemical changes of developing oocytes in the ovary of the Japanese killi-fish, medaka (Orzias latipes). The morphology of the ovary and the minute structures of develping oocytes are described with special reference to the formation of micropyle, chorion (egg membrane) and attaching organ (Figs.1, 2, 3, 4, 5). In the cytochemical studies, protein, lipoid, polysaccharides and nucleic acid are detected with the following methods or reactions: for protein, Salzar's, Millon's or Romieu's methods and the xanthoprotein reaction; for lipoid, Ciaccio's method and the method of frozen section; for polysaccharides, Bauer's and Hotchkiss' reaction; for nucleic acid, Feulgen's reaction. The results are as follows: 1. The chorion and the attaching organ contain at least protein and non-acid polysaccharides. 2. Oil drops of the mature-egg are formed by fusion of fat granules which appeared at first in the perinuclear cytoplasm of the oocyte. 3. The cortical alveoli of the mature egg are identical with the “vesicles” appeared in the young oocyte, which are formed at first in the neighborhood of the oocyte nucleus at the time of appearance of fat granules. The “vesicles” in the young oocyte or the cortical alveoli of the mature egg contain at least acid polysaccharides, and from the results of cytochemical reactions (Lison's method for polysaccharide sulfate compound and the other methods used) and of the staining affinity to mucicarmine, neutral red, etc., it is concluded that polysaccharides of the alveoli exist as a form of sulfomuco-polysaccharides (MEYER '45) which issimilar to the mucus found in every part of the tissue. 4. The existence of the lipoid wall of the cortical alveolus has been reported by AKETA ('54) in the same material, but the author could not find out such lipoid wall using the same method adopted by AKETA, i.e. Ciaccio's method. Furthermore, the alveolus prepared with KANOH's stripping method ('50) in formalin-fixed material does not stain with Sudan IV. Consequently, it is likely that the lipoid wall of the alveolus must be very delicate even if it is present.
In order to ascertain the general features of ovulation in Pisces and Cyclostomata, the present study was carried out using individuals of Oncorhynchus keta, CluPea pallasii and Lampetra japonica. 1. In Clupea pallasii, ovulated eggs are laid through the ovarian lumen and oviduct, while in Oncorhynchus keta and Lampetra japonica, the eggs emerge directly from the ovary which has no lumen, into the body cavity. 2. The maturation processes are completed within relatively short range of time in these species. In O. keta and C. pallasii, these processes are completed prior to ovulation, but in L. japonica the maturation proceeds only in the ovulated eggs. 3. A micropylar cell is found in the immature eggs of O. keta and C. pallasii (Text-Figs.4, 5, 7) as in Oryzias egg. It degenerates in the mature egg. There is no micropylar structure in L. japonica. 4. In all three species, the emergence of an egg from the lamella of the ovary at the time of ovulation occurs in the definite preexisting region (follicular rupture) as in the well-known case of amphibian eggs (Pl. I, Fig.3 & Pl. II, Fig.7) and in this region the theca folliculi is not found. At the time of ovulation, hypertrophy of theca folliculi and follicular cells is detected.
Mackerel fishing by ‘hanezuri’* has been carried out by fishermen in the coastal waters off Hachinohe, Aomori Prefecture, since the first trial by the research boat “Chiba-maru” (36.78 ton), Chiba Prefectural Fisheries Experiment Station, in the summer, 1951. During July 24-August 2, 1955, the Chiba-maru tried the ‘hanezuri’ off Hachinohe, and in adjacent southerly waters off northern Iwate Prefecture (Fig.1). The present writers were on board in the cruise, and examined the fishing ground, migration and the food of the mackerel, obtaining following results: - 1. Mackerel fishing by ‘hanezuri’ was successfully possible in the sea off northern Iwate Pref. in the summer, 1955 (Table 1). The surface water temperature in the fishing ground was 19.8-22.0°C, and coastal currents were flowing to south. The mackerel schools were consisted of Pneumatophorus japonicus (HOUTTUYN) only, and the folk length of individuals was more or less 30cm. Gonads were all immature. The fishing stations were sometimes indicated well by flocks of sea birds on the surface of the sea. 2. The migration was studied by tagging method. 332 individuals were tagged during the expedition. Among them 5 individuals were caught by trap-nets on the coast of southern Iwate Pref. They migrated to 110km south in 15-23 days (Table 2). 3. The food of the mackerel taken of Kuji, in northern Iwate Pref., was mainly composed of following animals: Engraulis japonica TEMM. & SCHL., Euphausia pacifica HANSEN and Calanus plumchrus MARUKAWA. The predominating constituent was not similar qualitatively in ten stomachs obtained around a station in the same time (Table 3). This may be caused by considerably irregular distribution of the populations of each food animal in the coastal water.
In this note the present author has annotated on twelve unrecorded species of fishes with brief descriptions, to be included into the ichthyofauna of Echigo and Sado, Japan, and two species which are thought to be omitted from the ichthyofauna of this region. 1. Among the fishes to be added herein, there are two kinds of remarkable and rare subtropical fishes, which are young Diproprion bifasciatus and medium sized Therapon theraps. It should be mentionel that Sado and its neighbouring region are northern limit for their occurrence. The counts and measurements of the specimens of these two species are as follows: - (1) Diploprion bifasciatus KUHR et VAN HASSELT Total length 39.8mm, body length 30.5. Head 2.5 in body length; depth 2.3; snout 2.7 in head; eye 3.6. D. VIII, 15; V I, 5 and A II, 12. Second and third dorsal spines remarkably filamentous, whose length 38 and 63mm as measured to tip of filament respectively. Body strongly compressed laterally, color generally yellowish white (Fig.1). (2) Therapon theraps CUVIER et VALENCIENNES Total length 132, body length 108. Head 3.2 in body length; depth 2.3; snout 3.5 in head; eye 3.6. D. XII, 10; V. I, 5 and A. III, 8; with a strong opercular spine. Four straight longitudinal dark bands running lateral body, and a blackish blotch lying from third to seventh dorsal spines. Lower jaw protrude somewhat beyond upper jaw. This species is unrecorded form from the western coast of Honshu, Japan Sea (Fig.2). 2. Two rare boreal or deep-sea fishes of central Japan, which are referable to the families Cottidae and Zoarcidae respectively, were found in the Sado Channel. These were reported as new species from Toyama Bay by MATSUBARA (formerly SAKAMOTO) and KATAYAMA respectively. They are: - (1) Marukawichthys amburator SAKAMOTO, 1931 Two specimens, body length about 160, collected by the Japan Sea Regional Fisheries Research Laboratory. (2) Petroschmidtia toyamensis KATAYAMA, 1941 One specimen, total length 313, collected by the Japan Sea Regional Fisheries Research Laboratory. 3. A scorpaenoid fish, Sebastes matsubarai HILGENDORF and an ophidioid fish, Lycogramma zesta (JORDAN et FOWLER) are thought to be excluded from his former list.
In this notes the author has enumerated twelve unrecorded species of fishes with brief descriptions, to be added into the ichthyo-fauna of Province Echigo and Sado Island of the Japan Sea. Among these fishes, there are eight offshore bottom fishes, which were caught by motor trawler on the northern fishing grounds of this region. They are: 1. Breviraja isotrachys (GÜNTHER) 2. Lutjanus vitta (QUOY et GAIMARD) 3. Sebastes itinus (JORDAN et STARKS) 4. Ainocottus ensiger JORDAN et STARKS 5. Malacocottus gibber SAKAMOTO-MATSUBARA Three examples. This was known only from Toyama Bay previously. 6. Hypsagonus quadricornis (CUVIER et VALENCIENNES) Three examples. This species has never been recorded from the western coast of the main land of Japan. 7. Champsodon snyderi FRANZ Not very rare. 8. Acanthopsetta nadeshnyi SCHMIDT Rather rare. Following four species of shore fishes were caught on the coast of Ryotsu Bay, Sado Island, which are also unrecorded from this region. 9. Trachyrhamphus serratus (TEMMINCK et SCHLEGEL) 10. Duymaeria flagellifera (CUVIER et VALENCIENNES) 11. Furcina oshimai JORDAN et STARKS 12. Pseudoblennius zonostigma JORDAN et STARKS
In this report the author has further more enumerated sixteen unrecorded species of fish with their brief description, which are to be included into ichthyofauna of Province Echigo and Sado Island of the Japan Sea. Amoung these fish, there are twelve shore fish and tide-pool fish, which were caught by hand net, set net prepared for yellow-tail, gill net for flying fish, and by rod line in the vicinity of Sado Marine Biological Station. For the following asterisk marked six fish, it is considered that the locality is the northern limit for their existence. 1. Cypselurus opisthopus hiraii ABE 2. Cypselurus heterurus döderleini (STEINDACHNER) *3. Iso flos-maris JORDAN et STARKS *4. Eviota abax abax (JORDAN et SNYDER) *5. Pterogobius elapoides zonoleucus JORDAN et SNYDER *6. Aspasma ciconiae JORDAN et FOWLER 7. Echeneis brachypiera LOWE *8. Tripterygion bapturus (JORDAN et SNYDER) *9. Dasson trossulus (JORDAN et SNYDER) 10. Azuna emmnion JORDAN et SNYDER 11. Ernogrammus hexagrammus (TEMMINK et SCHLEGEL) 12. Pterophryne ranina (TILESIUS) The following four species of deep sea bottom fish were caught by motor trawler of the coast of Suizu of Sado Island in middle Japan. They are also the species unrecorded hitherto in this locality. 13. Breviraja smirnovi (SOLDATOV et PAVLENKO) 14. Lumpenus macrops MATSUBARA et OCHIAI 15. Lumpenella nigricans MATSUBARA et OCHIAI 16. Gengea japonica KATAYAMA