While engaging in the ecological study of Muraenesox cinereus (FORSKAL) taken from the Inland sea of Japan, we found a interesting species closely related to the former. Upon careful examination of this fish, it was found to represent a new species, and described heren as Muraenesox yamaguchiensis. We wish to express our hearty thanks to Prof. Kiyomatsu MATSUBARA for his kindness extended to us in various ways. We are also greatly indebted to Mr. Akira OCHIAI and Mr. Tosio YosioKA.
Since the publication in 1952 of the “Concluding remarks” for a series of his papers dealing with the classification of the puffers (Tetraodontidae, Teleostei) from Japan and adjacent regions, the writer has received by the courtesy of Mr. D. AOKI (Manazuru), Mr. J. BOHLKE (Stanford Univ.), Dr. W. A. GOSLINE (Univ. of Hawaii), Dr. B. W. HALS-TEAD (School of Trop.Prev. Med., Loma Linda, Cal.) Mr. Kintaro SEKINE, his son, Hidekazu SEKINE (Tokyo), Dr. J. L. B. SMITH (Rhodes Univ.), Dr. I. TOMIYAMA (Tokyo Univ.), Dr. A. B. WALKOM Director, Australian Mus.), Dr. G. P. WHITLEY (Australian Mus.) and Mrs. YANAGISHIMA (Kyoto Univ.), some additional old and recent papers as well as additional old and fresh specimens of puffers. Furthermore, he has received from Dr. Carl L. HUBBS (Scripps Inst. Oceanogr.) and Dr. WHITLEY information and kind advices regarding the usage of the generic and subgeneric names of the Japanese puffers, which the writer, so to speak, continued to integrate step by step during 1939 - 1952 handicapped by lack of not a few important public itions and specimens. The aim of the present paper is to correct some of his earlier mistakes and to add records of rare puffers. He takes great pleasure in expressing here his sincere thanks to the lady and gentlemen mentioned above by name for their kindness and cooperation with him.
1) On July 7, 1953, at SHIKANOSIMA, near FUKUOKA CITY, the authors operated artificial insemination of Siganus fuscescens (HOUTTUYN) and observed the development of the egg and reared the hatched larva for about 90 hours. 2) Hatching took place in about 27 hours at the water temperature 23.5-26°C. 3) The egg is colorless and transparent, spherical in shape, demersal and strongly adhesive in nature, measuring 0.62-0.66mm. in diameter, with 4-7 large colorless oilglobAes measuring 0.10-0.15mm. in diameter accompanied by several smaller ones. 4) The process of development is much he same with that of other teleosts. In 1 hour and 10 minutes it finished the 2nd divission; in 2 hours and 45 minutes it attained early morula stage; in 7 hours and 45 minutes the blastopore closed. In 10 hours and 45 minutes the Kupffer's vesicle and the notochord were formed, as well as 6 myotomes in the middle part of the embryonal body. In 15 hours and 30 minutes the Kupffer's vesicle disappeared and the number of myotomes increased to 23. In 21 hours and 45 minutes stellate melanophores appeared in front of eyes, and scattered all. over the body and on the surface of the single fused oil-globule. 5) The newly hatched larva is 2.60mm. in total length, with the myotome number 8+16=24. No pectoral fins have yet been formed. The yolk is oval in shape, containing only one oil-globule measuring 0.19mm. in diameter. The oil-globule is seem protruded from the anterior part of the yolk. The stellate melanophores are founded in front of eyes, along the ventral side of abdomen, and on the ventral edge of from 9th to 18th caudal myotome, as well as the surface of the yolk and oil-globule. In 20 hours after hatching the pectoral fins appeared and the oil-globule became included' in the reduced yolk again. In 48 hours after hatching, the eyes became black and the mouth opened. The yolk had been almost absorbed.
Chaenogobius castanea O'SHAUGHNESSY is a small goby, most common in estuaries and shores of Japan throughout, where it passes the whole period of its life history. The external characters of the fish such as the coloratoin and color-pattern, and the number of the fin-rays, spines, vertebrae, scales and gill-rakers are so variable that many species have been established from the same fish from different localities. The spawning season extends from January to April in the vicinity of Fukuoka City, Kyushu. The male adult generally attains a smaller size than the female (Fig. 1). Before spawning, the ripe male prepares a room for breeding, usually utilizing the vacant living-hole of a kind of shrimp, Upogebia major DE HAAN, which is common in the shallow sandy bottom of the estuary. Often a couple of parent fish were observed in that hole. The eggs are deposited on the inner wall of the hole, about 1 cm. in diameter and 5-10cm. deep.The female parent lieves the hole soon after spawning, while the male stays there guarding the eggs until they hatch out (Fig. 2). The spawned egg is rather large and club-shaped, about 4.1mm. in length, about 1.3mm. in width (Fig. 3). The newly hatched living larva is 7.mm in total length. The larvae, 10-16mm. in total length, are found to live a pelagic life in the bay, mainly feeding upon copepods. The juvenile at about 20mm. in total length commences a bottom-life, when the feeding habit changes into an omnivorous one. The formation of the color-pattern on the bodyside is very slow, attaining its completion at the total length over 40mm. (Fig. 4). Specimens, collected in the vicinity of Fukuoka City show the male to grow to 37-51 mm. in total length in a year, 49-55 mm. in 2 years and over 55 mm. in 3 years, while the female to 40-56 mm. in a year, 56-64 mm. in 2 years and over 64 mm. in 3 years.
In this paper the writer deals with the breeding habits of the fresh-water suker, Abbottina rivularis (BASILEWSKy), a small cyprinoid fish. The usual habitats of the fish are the slow streams with muddy bottom. The spawning season lasts from beginning of March to early May. In the breeding male numerous horny tubercles appear on the snout, anterior part of the cheek, pre-opercle region and on the outer margin of pectoral fins. Dusky and yellow nuptial coloration also appears on the body. The male fish prepairs a nest on the muddy bottom in the shape of a round, shallow depression, 20-40 cm. in diameter and 3-5 cm. in depth. In this nest about 2, 000-4, 000 eggs are deposited, over which the male parent fish eagerly keeps guard until the hatched larvae attain the end of the post-larval stage, about 10mm. in total length. The egg is spherical in shape and about 1.4mm. in diameter, with a jelly-like coating of about 1mm. in thickness. The surface of the jelly coat is covered with mud.
Salarias enosimae JORDAN et SNYDER is found in the rocky tide-pool near high water mark in Southern Japan to Ryukyu Islands. The spawing season at Nobeoka City, Miyazaki Prefecture, extended from late June to early September in 1953. The eggs are deposited in a single layer on the under surface of flat stones, or inner wall of the crevices of the pool. The male parent fish guarded the eggs. The behavior of the guarding male is shown in the figure III. Usually he puts out his head from the crevice as the figure III, (8). Sometimes he goes out for feeding in the pool. When he comes back to the crevice to guard his eggs he acts as is shown in the succeeding figures of the figure III. As he returns near the crevice he stops for a moment (1); then advances to just before the entrance of the crevice (2); turns his body (3); enters from his tail (4); sends water in the crevice by fanning his tail (5); he sends water to the mouth of the crevice by the motion of pectoral fins (6); then his body disappears in the crevice (7); soon after he puts out his head again from the crevice (8). After the succeeding motions from (4) to (8) are repeated several times, he goes out again for feeding. The number of the spawned eggs in one mass varies from 5, 500 to 40, 000 (table 2), containing egg groups of different developmental stages, showing that the spawning was induced several times by the same male. The egg is colourless, somewhat flattened sphere in shape, measuring 0.79-0.88 mm. in diameter with a single large oil-globule measureing 0.25 - 0.29 mm. in diameter, accompanied by several smaller globules, and firmly attaches to the rock wall. The hatching takes place in a week at the water temperature 24.8-31.2°C. Newly hatching larva is 3.5-3.7mm, in total length, with large fan-like pectoral fins marginally pigmented with black blotches.
The part three of this article contains descriptions of life colors and some interesting notes on the fishes found in Suruga Bay. The interesting species are as follows: Gymnothorax berndti (=richardsi?); very young stages (17.5-22.5mm.) of Scombrops boöps ; Sphoeroides hypselogenion; Lagocephalus sceleratus; Gobius otakii; Calliurichthys doryssus and Callionymus virgis.
Numerous cortical alveoli are embedded in unfertilized eggs of the goldfish (Carassius auratus) and the pond smelt (Hypomesus olidus). The most prominent feature of cortical changes at the time of fertilization is a wave-like release of the content of cortical alveoli into the interstice between the plasma membrane and the preexisting egg membrance. This change and the subsequent separation of the egg membrane begin at the animal pole and end at the vegetal pole. The separation of the egg membrane is due to a colloid osmotic pressure of the perivitelline fluid which is derived from cortical alveoli. Essentially similar cortical changes are induced when ripe unfertilized eggs are immersed in distillled water, fresh water or M/7.5 Ringer's solution which is nearly isotonic to eggs. This may be regarded as an activation. Time required for completion of cortical changes is dependent on salt concentration of media. In the egg of the goldfish, it requires about five minutes in distilled water or fresh water whereas it is twenty minutes in M/7.5 Ringer's solution (20-22°C). The same is true when inseminated (dry method) eggs are immersed in distilled water, fresh water or Ringer's solution. In distilled water or fresh water, released content of cortical alveoli remained as opaque granules in the perivitelline space for a considerable period of time. In Ringer's solution they soon disperse in the perivitelline space. No cortical changes of the unfertilized eggs take place when an isolated ovary is kept in a moist chamber. Auto-activation is inhibited in the ovary or in theovarian fluid. In the isotonic soluton of sodium oxalate (M/11) which precipitates Ca ions, cortical changes are reversibly inhibited. When unfertilized eggs of the goldfish are activated by immersing them in fresh water for five minutes and then inseminated in the solution, a few eggs are fertilized and developed into embryos. This shows that the sperm can enter the egg in which cortical changes are nearly completed.
In the series of experiment, we have done and doing, to see the fish behavior toward various sorts of characters of fishing nets, scince these are a sort of model experiments in tank, we should select the fish species to use as to be small size proportional to that of the model net and as to alive actively through out the period of experiments. Moreover, as the actual commercial fishing net is usually deviced so as to catch a certain kind of fish mainly, in model experiments we should select a minuature fish which can fairly represent the habit of it. On the other hand, so various kinds of fish have so various peculiarities according to the range of living and habit of swimming, and about it also we are adding more knowlege in recent days by ultra sonic fish locater and others. Set nets, including pound net and others, a group of fishing net kinds usually called “Teichi-ami” here, having long fence net or leader attached to the pocket or box, can catch any sort of fish which pass through the area where the net is set, though main turget is some narticular fish. In the course of studies on the screening effect of fence net, usually using “medaka”, Aplocheilus (Oryzias) latipes, the common rice paddy minnow, as the minuature fish for model experiments, we became to anxious that if other fish species which has other sort of habit is used what result would be, obtained. And we thought such a knowlege would adds some to the deductive interpretaion of the result of this sort of model experiment. The fence net or leader of set nets is usually spread out from the bottom up to the surface of water, however the screening effect of it would differs according to the fish kind in various parts of the net, if it is considered to be devided according to the stratum in depth of water. Especially, in recent years, set net is deviced to sink below the water surface to avoid the rough wave of the surface caused by stormy weather, so fence net, as a part of it, also has possibility to be set underwater, having its float line or cork line beneath the water surface. Therefore, in the following experiments in tank, as the under water fence net a nylon film (opaque) of various hights was set at the middle of the tank, and the passing rate was observed about several kinds of fish having different habit of living. The first serries of the experiments was done by the hand of Keikichi KONDO, (Research student) and the latter part was done by Masakazu YAO (now a member of Tohoku Region Fisheries Research Institute) as a graduation thesis when he was a student, and the plan and the compilation was made by Yoshio HIYAMA.