Two alepocephalid psecimens were captured in 1973, approximately 2000 m depth off the west coast of the island of Hawaii. The specimens, tentatively identified as Alepocephalus blanfordii Alcock, represent the first record of the family from Hawaiian waters.

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Of the Japanese Mustelus species, M.griseus Pietschmann establishes the placenta during gestation.Formation and structure of the placenta in M.griseus were histologically investigated.During early gestation the internal surface of the uterus is lined by the stratified cuboidal epithelium.However, as the gestation advances, the internal uterine surface changes from a stratified cuboidal epithelium to a simple columnar one.The placenta consists of two portions: the maternal placenta (internal uterine wall) and the foetal placenta (yolk sac wall).Between these two tissues the embryonic membrane exists.The epithelium of the maternal placenta is considerably thinner than that of the other part of the same uterus.The epithelium of the foetal placenta is also thinner than that of the other portion of the same yolk sac wall.When the embryos grow more than 150 mm in total length, both epithelia of the foetal and maternal placenta almost degenerate.At the foetal-maternal junction of a definitive placenta, the well developed capillaries of maternal tissue and those of foetal tissue come in contact with both sides of the embryonic membrane.

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Caprodon unicolor is described as a new species in the fish family Serranidae, subfamily Anthiinae.This new fish was captured off Midway Island, North Pacific Ocean.It is closely related to C.schlegelii (Günther), but differs in coloration, number of gill-rakers, shape of maxillary, and shape of caudal fin.

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The stratum granulosum of the pyloric caeca in the rainbow trout, Salmo gairdneri Richardson was examined by electron microscopy.
The stratum granulosum was found in two regions;stratum granulosum internum and externum lying inside and outside the stratum compactum respectively. The two layers are composed of morphologically similar granule cells which are in an elongated oval or spindle form, protrude a few cytoplasmic projections from their cell surface and closely appose to the fibroblasts, and they are connected with each other and/or fibroblasts by desmosomes.
In the fingerlings about 3 weeks after starting on a course of feeding the granule cells, containing no or a few immature granules, are provided with an oval nucleus located at their central portion, the comparatively well-developed Golgi apparatus and rough endoplasmic reticulum, a small number of mitochondria, centrioles, and plentiful free ribosomes.
In the fingerlings about 5 months after starting on a course of feeding the stratum granulosum internum was composed of the granule cells which mainly contained electron lucent granules (about 340-450mμ in diameter) with gradations in electron density, and which exhibited about the same degree of development in cell organelles as those in the fingerlings about 3 weeks after starting on a course of feeding and frequently contained lysosomes.On the other hand, the stratum granulosum externum was composed of the granule cells which were packed with electron dense granules about 600-1160 mμ in diameter and were provided with an eccentrically located nucleus with occasional deep infoldings, less-developed cell organelles such as the rough endoplasmic reticulum and the Golgi apparatus, a few mitochondria, and free ribosomes.Formation of the granules appeared to be closely related to the Golgi apparatus.
In the rainbow trout about one year after starting on a course of feeding the granule cells in both stratum granulosum internum and externum exhibited about the same ultrastructural appearance in the degree of development in cell organelles as those in the stratum granulosum externum of the fingerlings about 5 months after starting on a course of feeding, and the externum was frequently composed of 2 layers of the granule cells, some of which contained electron lucent granules (about 340-450 mμ in diameter) with gradations in electron density.
The tunica muscularis consists of 1 or 2 layers of internal longitudinal muscular fibers (tunica muscularis longitudinalis interna), 5 or 6 layers of intermediate circular muscular fibers (tunica muscularis circularis intermedia) and 4 or 5 layers of external longitudinal muscular fibers (tunica muscularis longitudinalis externa).

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The development of the seven transverse bands on the sides of Oplegnathus fasciatus (Temminck and Schlegel), which had been reported mostly on larval fish collected from the field, was traced from artificially fertilized eggs to juvenile stage under laboratory conditions.Observations on the growth, behavior, feeding, and changes of color and markings were made on specimens selected with adequate intervals.The works were conducted in May, 1972 and 1973.The observations are summarized as follows.
The formation of the cross-bands is commenced with the larva of about 8 mm in total length about or 20 days after hatching, and completed at about 20 mm or about 35 days after hatching at the water temperatures of 18.5-23.7°C.The process of cross-bands formation can be divided into nine stages as illustrated and tabulated.Stages correspond more closely with the size of the fish than with the age of fish after hatching.
The gathering behavior of larval fish toward floating seaweeds, as observed in the field, was confirmed by placing seaweeds in the rearing tank.The behavior occurs first in the fish about 11 mm (8-12 mm) long which is the Stage 2 of the bands formation.It is also confirmed that the process of the bands formation is not affected by the presence or absence of the floating seaweeds around the larvae kept in the rearing tank.It can be said that the development of the bands during the larval stage is an intrinsic character of the species.Whereas, the change of the ground color of the body into bright brownish yellow in the juvenile staying around or among the floating seaweeds is considered as an adaptation, as such color change is less clear in those kept in the rearing tank without floating seaweeds.
The diet can be changed from natural organisms to minced fish meat most efficiently in the larvae of about 12 mm long which is about one month after hatching or the Stage 5 of the cross-bands formation.It was suggested through the observations that the status of the bands formation can be used as an indicator for determining timing in rearing fish larvae, for feeding, exchange of tank water, transfering the larvae from the tank to the floating cage in the sea.

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Synechogobius hasta (Temminck et Schlegel) is one of the largest gobioid fish, attaining to about 50 cm in total length, and is abundantly distributed in Ariake Sound which is situated on the west coast of Kyushu.The fish lives in the muddy shallow region of the sound and makes a burrow in the mud for spawning.From 1969 to 1973, spawning of the fish was observed in the aquarium, and spawning behavior, embryonic development, and morphology of larvae and juveniles were studied.
The adult of the fish has following sexual characters (Fig.2).The female has a genital papilla with a rounded end, whereas the male has one with a pointed end.The male has enlarged lips and developed jaws, so that the head is nearly U-shaped in dorsal and ventral view, whereas the head of the female is nearly V-shaped.The male is bright brownish dorsally and yellow ventrally and colors get brighter along with sexual excitement.The female is always dull brown dorsally and white ventrally.
Pair of mature fish, administered some gonadotropic hormone injections, were shut in an earthen pipe or an opaque vinyl chloride pipe, 8-9 cm in diameter and 60 cm in length, closed with net at both ends.The pipe was set in the aerated aquarium (Fig.4).
Spawnings occurred in March and always in the morning.At the spawning, parent fish, being upside down in the pipe, laid 15, 000 to 51, 000 eggs in one layer on the upper wall of the pipe during 2 to 4 hours (Fig.5).The fish laid all eggs at a time.The parents ate a considerable number of their own eggs.
The degree of egg adhesion to the pipe wall varies by egg mass, seemingly dependent on egg quality such as fertility and vitality.
Eggs were almost spherical in shape just after spawning.They got larger and club-like in the early developmental stages, measuring 4.9-6.6 mm (5.5 mm) in longer axis and 1.0-1.2 mm (1.1 mm) in shorter axis.
Development of egg is shown in Table 2 and Fig.6.Hatching took place about 15 days after spawning at 13.0 18.9°C in water-temperature.
The egg in the early stage had many small oil globules in the yolk, measuring 0.02-0.08 mm in diameter, which finally united into one before hatching.
In many of egg masses, there were often observed agrippa eggs.In normal egg, the embryo formed primarily on the lateral position of the egg.It shifted the position to near the top of the egg according to the rotation of embryo and yolk in the progress of blastopore closure.After the rotation of embryo, its tail prolonged towards the basal end of the egg.In abnormal egg, the rotation of embryo and yolk failed to occur, so that the embryo kept on the lateral position of the egg was provided with the tail near the top of the egg and the tail prolonged towards the opposite direction to the normal one (Figs.7 and 8).
It was also often observed that the embryo fell out of the egg before the development was completed.These abnormally hatched larvae died in some days after hatching.Abnormal hatching tended to take place in the egg masses with many agrippa eggs.
Just hatched normal larva, measuring 6.1 mm in total length, had a little yolk, the rudiment of the caudal fin, cupulae of neuromasts, and 36 myomeres (12+24).The larva boremelanophores on the ventral ridge of breast and tail, air-bladder, and dorsal and ventral parts of the intestine.
In 14-18 days after hatching, most of individuals attained the total length of about 12 mm and were provided with cup-like pelvic fin.And shortly after that, they entered into the bottom life.Beginning of scale formation and completion of nostril were in the stages of about 10 mm and 17 mm in total length respectively.

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[in Japanese]

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[in Japanese]

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Specimens of a dwarf goby which agree well with the holotype of Gobius javanicus Bleeker, were obtained from Okinawa Prefecture.They agree also with the description and figure of Vaimosa piapensis Herre.A new Japanese name“sunagohaze”is given for this species.As stated by Aurich (1938: 160), the generic name Pseudogobius Popta should be adopted for this species, and thus, Pseudogobius javanicus (Bleeker) is appropriate scientific name.

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Tomiyama (1963: 70) recorded two small gobiid specimens from Yakushima and Okinawa jima, Japan, identified them asGobius tessellata (Herre) and proposed Japanese name “hinahaze”. Our examination of the two specimens revealed that they are different from the original description and figure of Vaimosa tessellate Herre, but agree well with the original description and figure of Vaimosa bikolana Herre and Vaimosa montalbani Herre and the types of Stigrnatogobius minutus Takagi. V. montalbani and S. minutus are considered as junior synonyms of V. bikolana. It was made clear that the genus Redigobius Herre is most appropriate among the generic names adopted for V. bikolana, on the basis of comparison of respective type species.

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