カサゴの研究―6 : 精子形成の電子顕微鏡的研究

The Spermatogenesis and the structure of spermium of marine ovoviviparous teleost fish, Sebastiscus marmoratus, was observed by electron microscope. The author had formerly studied this problem by optical microscope, but the division of spermatozoa was observed erroneously in that study. During the sexual resting period, there is no spermatozoon in the seminiferous tubules of this fish, but in June the spermiogonia appear from the basement membrane under the seminiferous epithelium. The spermato-genesis of this fish is classified into two periods, one is multiplying period and the other is developing periods. In maltiplying period, the spermiogonium which appears on the basement membrane is divided repeatedly ane grow into many spermatozoa in a cyst. A cyst originates from a spermiogonium, and the growing stage of the spermatozoa in a cyst is quite equal, but different from that of the spermatozoa in any other cyst within a seminiferous tubule. During the developing period after the multiplying period, the nuclear contents of the spermatozoa in the cyst are granulated and all the granules are collected at one end of the nucleus and finally become the sperm head. There is no head cap in the sperm head of this species. And then the mitochondorias in the protoplasm gather at one end and when the nuclear contents begin to grow in granular condition, the tail flagella appears from the nucleus and is surrounded by the mitochondorias. The tail flagella grows longer along with the progress of nucleus (sperm head). The number of mitochondorias around the tail flagella of this species is less than that of mammals. The mitochondorias are not in immediate contact with the tail flagella but packed by the mitochondorial sheath at the surroundings of the base of tail flagella. The tail flagella consists of a central pair of tail axial fibril and nine pairs of fibril surrounding it.!?1. The testes of Sebastiscus marmoratus, a marine ovoviviparous teleost fish, in the reproductive season were collected, and the spermatogenesis and the structure of spermatozoa were observed by electron microscope. 2. Daring the sexual resting period, there is no spermatozoa in the seminiferous tubule and a layer of seminiferous epithelium is present on the basement membrane in the seminiferous tubule. 3. In June, the spermiogoniums appear from the basement membrane under the seminiferous epithelium of the seminiferous tubule. 4. The nucleus of spermiogonium is large and its protoplasms are rather few. Many of mitochondorias in the protoplasm are arranged around the mitochondorial rosettes. 5. The mitochondorias of this spermatozoa are circular in shape, and the cristaes of mitochondoria are irregular

ミナミヌカエビ(タエビ)Neocaridina denticulata De HAANの発生および成長について

1) Neocaridina denticulata DE HAAN is not most popular fresh water shrimp in the south-west of Japan, but owing to the diffusion of the insecticides in the paddy-field after the war, it is going to be annihilated. On the one hand the demand to this shrimp has increased as it is the most desirable live-bait in the coastal sea. We has studied about the behavior of this shrimp since the autumn of 1958 to know the way of its propagation and in this paper we report about the development and growth of this shrimp. 2) We collected this shrimp from the pools among the mountains in the neighbouring of Sasebo city. 3) Our shrimp has many variations in body color but the many are semitransparent grey green, the blackish brown comparatively and the reddish sometimes. 4) The differences of both sexes in the adult of this shrimp are following, (1) the size distribution of females is larger than males, (2) at the Ist pleopod of this shrimp the exopodite is normal slender form and the endopodite is very large and pear-shaped in male, but in female the endopodite is smaller and more slender than the exopodite and is not seen the special form such as male, (3) at the 2nd pleopod the endopodite and exopodite are almost same size in female but in male the exopodite is larger and the other is very smaller, and the endopodite is attached to the enlarged and thickened appendix masculina which has many setae. 5) Our shrimp has the special number in the dorsal and ventral teeth at rostrum, in the spines of the both sides at the dorsal face of telson and in the spines at the terminal margin of telson as the tables show. 6) After hibernation the male molts at the middle of April and the female spawns the eggs and holds this eggs in his pleopods, and the hatching is performed in the period from the middle decade of May to the last decade of June, this is the first hatching season in this year. 7) The egg of this shrimp is larger than the other, and the number of eggs in this species is very few in comparison with the other and there is a positive correlation between the body length and the number of eggs. After the spawning the eggs adhere in the pleopods by the elastic fibroid egg handle. 8) The shape of the young shrimp after the hatching is almost the same to the parent except the telson and uropods as the PLATE Ⅷ shows. This shrimp does not metamorphose. 9) The figures of the body, antennas, mandible, maxillas, maxillipeds, pereiopods. pleopods, telson and uropods are shown at PLATES in the each larval stages. 10) In the shrimp after the 5th molting (after about 10 days from the hatching), there. is no yolk in the carapace and the color of the excrement changes so it is seemed that the shrimp after the 5th molting begins to take the food. Its growth from this. stage is rapidly. 11) In the young shrimp which grows up about 11mm in body length after a month from the hatching, the characteristic of the sex already appears and the both sexes can be distinguished by Ist and 2nd pleopods, it is guessed that the gonad matures in both. sexes since this time. 12) The shrimp which grows up about 16 mm in body length after two monthes front the hatching molts the eggs which has held between the pleopods, namely this is the second hatching season in this year and it is the period from the first decade of August to the middle decade of September. The molting and development of this larval shrimp which had hatched out in this hatching season is same to that in the first hatching season. And the parent shrimp in the first hatching season does not perform the spawning and hatching. 13) The growth curve of this shrimp is indicated in Fig. 6. 14) This shrimp has been alive more than two years at least. 15) This shrimp is very delicate to the chemicals such as insecticides, but is not so delicate for the change of natural environments such as the water temperature and its growth is rapidly and the period which reaches to the sexual maturity is short and its food at the breeding is the rice-bram and so on which is very easy to receive, So the propagation of this shrimp is not difficult

水中音に関する研究―I : 日本近海産Alpheus属の水中音について

Four species of the genus Alpheus FABRICIUS, so-called snapping shrimps, namely A. bis-incisus de HAAN, A. brevicristatus de HAAN, A. rapax FABRICIUS, and A. japoni-cus MIERS, were caught in the coastal waters of Nagasaki Prefecture and their under-water sounds were recorded. These shrimps emit peculiar pulse which is very powerful. These sounds are emitted by striking of the inside projections of their large chela. The duration of this sound (pulse) is less than 18 millisecond and the frequency band reaches more than 7kc. It seems that the frequency of the sound emitted by individual specimen is less than 1 per second. The mechanism of emitting the sound varies by species but their sounds are all pulses which resemble closely. Furthermore, a sound spectorogram differs in detail from any other even in the same specimen. In effect, it is guessed that the underwater sound (pulse) emitted by genus Alpheus constitutes the largest part of"FRYING NOISE"

サメ類の研究-11 : エドアブラザメHeptranchias perloの雌の生殖について

The present report is to investigate the morphology and ecology of reproductive system of female Heptranchias perlo (BONNATERRE) in the southwestern waters of Kyushu. H. perlo belongs to the non-placental type in viviparity and does not form the uterine compartments. Both right and left ovaries of this species are functional each containing 10 mature ova measuring 35 mm to 45 mm in diameter on the average at the time of ovulation. Moreover, the ova in ovary do not develop with the growth of embryos but after the parturition. The sexual maturity of female is reached between 95 cm and 105 cm in total length as estimated from the correlation of total length with the diameter of ovum in ovary and the uterine width. It seems that this species has no specific reproductive season judging from the situations of ovaries and uterus. The embryos measuring about 240 mm in total length were similar to the adults in general body proportion and coloration, and were not enclosed in the embryonic membrane. Further, these embryos appeared to be just before parturition, since each embryo had no external yolk sac but internal yolk sac attached to the duodenum, supplying the yolk substance to the valvular intestine. The condition factor and hepatosomatic index are greatly related to the reproduction of female H. perlo.本研究では、九州南西海域のエドアブラザメHeptranchias perloの雌の生殖形態及び生態を調査した。本種は,手島らのサメ類の雌の生殖形態の分類による胎生非胎盤型に属し,子宮隔室を形成しない種である。本種の卵巣は左右ともに機能的であり,排卵直前の成熟個体は,卵径35～45mmの完熟卵を左右平均各10個持っている。更に,卵巣卵は,胎児の成長に伴って,発達せず,胎児の出産後に発達すると考えられる。本種の雌の成熟体長は,全長と卵巣卵の直径及び子宮幅との相関より求められ,全長95～105cmであると推測される。卵巣卵あるいは,子宮の状態から判断して,本種には,特定の生殖時期がないと考えられる。全長約240mmの胎児は,ほとんど成体と変らない体型及び体色をし,胎児膜に包まれていない。これらの胎児は,外卵黄のうを持たず,容積0.1～1.7mlの内卵黄のうを十二指腸部に付け,腸に卵黄を供給しているため,出産間近の胎児であると考えられる。肥満度及び肝臓体重指数は,本種の雌の生殖に非常に関連している

台湾の淡水産カニ類について

The authors collected specimens of fresh-water crabs from 23 places in Taiwan. Ten species, including an undescribed species, were found: Eriocher japonicus, E. rectus, Varuna litterata, Varuna sp. (Grapsidae); Somoniathelphusa taiwanensis (Parathelphusidae); Nanhaipontamon formosanum (Isolapotamidae): Candidiopotamon rathbuni (Sinopotamidae); Geothelphusa chiui, G. Candidiensis and G. miyazakii (Potamidae). Distributions of some of these crabs are limited either in east or west of the central mountain range of Taiwan.台湾の全土にわたる23ヶ所において淡水産カニ類を採集し、次の5科10種を得た: Eriocheir japonicus, E. rectus, Varuna litterata,Varuna sp.(以上はGrapsidae); Somaniathelphusa taiwanesis (Parathelphusidae); Nanhaipotamon formosanum (Isolapotamidae); Candidiopotamon rathbuni (Sinosotamidae); Geothelphntsa Chiui, G.candidiensis, G.miyazakii (Potamidae). これらのうちVaruna sp.は未記載種と思われる。一部のカニ類の分布は地理的に偏在していて、Eriocheir recutusは東部にのみ、Somaniathelphusa taiwanensis, Nanhaipotamon formosanumおよびGeothelphusa chiuiは西部にのみ生息している。なお、Eriocheir rectus, Varuna litterataおよびNanhaipotamon formosanwmは中国大陸に、またEriocheir japonicus, Varuna litterata, Geothelphusa candidiensisおよびG.miyazaakiiは日本にも分布している

サメ類に関する研究-6 : エイラクブカの生殖

We made observations of Galeorhiuus japonicus, caught in the East China Sea and landed at the Nagasaki fish market. In this species, only the right ovary is fun ctional, and usually 8 to 22 fully developed ova are ovulated during the ovulating season. This species belongs to the viviparous non-placental category, the external yolk-sac disappearing immediately before parturition. During the gestational stage, the uterine compartments are formed. In the early gestational stage the uterine compartments are oriented transversely but as the gestation advances the compartments become more longitudinally oriented. The number of embryos contained in the both uteri is 8 to 22, depending upon the size of the shark. The nutrition of embryos depends mainly upon the contents of their yolk-sac. However, the greater the increase in internal yolk, the more the external yolk disappears. The intestinal activity begins when the embryos grow to about 70 mm in total length, and the intestine also functions as an embryonic organ of nutrition. This species grows to a maximum length of about 1.05 m in male and 1.2 m in female and the sexually mature male is about 85 cm long, while female ranges from 84 cm to 102 cm in total length, the variation in the female individuals being very large. The parturition season is June when the embryos, about 210 mm to 250 mm in total length, are born prolifically. The ovulation, mating and fertilization occur mainly from June fo August. The gestation period is approximately 10 months

サメ類に関する研究-10 : Heptranchias perloの生殖器官の形態学的研究

The present report is to compare the clasper and its constituent skeleton of Heptranchias perlo (BONNATERRE) with those of other sharks. Moreover, the relationship of total length with testes weight and clasper length of H.perlo is discussed respectively, and the total length at the maturity of male is estimated. Then comparison is made between the clasper cavity of H.perlo and the siphon sac of other sharks.!?1. The male reproductive organs in Heptranchias perlo with seven gill openings were morphologically and ecologically investigated. 2. Teeth of H. perlo are peculiar in their shape, especially in the lower teeth. 3. The present species does not appear to have any definitive reproductive season, as a result of examination of testes and sperm sacs of males and 4. Male reaches the maturity at its total length between 70 and 85cm. according to testes weight and clasper length. 5. The posterior part of the pelvic fin extends to form the clasper sheath. 6. Unlike most male sharks, H. perlo has no siphon sac. Instead of the siphon sac, H. perlo possesses the clasper cavity. 7. The skeleton of the pelvic fin is different in its shape from other species, especially in the pelvic girdle. 8. No accessory cartilages are attached to the stem cartilages. 9. The skeleton of the pelvic fin and the clasper is hardly calcified

全頭類の研究-2 : 長崎県沿岸域で捕獲されたギンザメChimaera phantasma JORDAN et SNYDERの生殖について

The internal sexual organs and reproduction of Chimaera phantasma caught in the coastal waters of Nagasaki were investigated. The testes of C. phantasma is that of seminiferous follicle type. The seminiferous follicles develop more in the region near the outer pole of the testis. Both ovaries are functional and each gonopores open separately without the cloaca. Some ova were covered in the capsule one by one at the nidamental gland, as in most Elasmobranchii, and the ova were spawned in succession in the same breeding season. Sexual maturity in females was apparently reached at a body length of about 63cm, while in males it was attained at about 51cm. The reproductive season of C. phantasma appears to last about a half year, with the peak activity during winter.1975年から1980年まで長崎沿岸域より採集された408個体(雄・164,雌・244)のギンザメChimaera phantasmaの生殖器官の調査を行った.本種の生殖腺の発達過程は板鰓類のそれとは全く異なるが,生殖器官の形態・様式及び精子形式の過程等は極めてよく似ている.そこで,ギンザメの生殖について板鰓類と比較しながら述べた.本種の生殖腺は多くの板鰓類と異なり,雌雄とも又左右いずれも機能的である.雄は体長約51cm,雌は約63cmで性的成熟体長に達すると考えられる.産卵直前の卵は直径40mm以上にもなり,連続していくつかの卵をカプセルにつつんで産出する.産卵期は冬期を中心にして半年近くの長期にわたるものと考えられる

九州西方海域産小型歯鯨類の研究―14 : 東支那海済洲島の南方海域で捕獲されたハセイルカについて

Delphinius sp., which is called HASE IRUKA (Hase dolphin) in Nagasaki, Japan, live in the west sea area of Kyushu. The authors investigated whether or not that dolphin is identified with SIEBOLD\u27s dolphin or Delphinus capensis, and is different from Delphinus delphis. As the result of the investigation on the body color, external proportion, and skull measurement, it was proved that Hase dolphin is identical to CGAWA\u27s Delphinus capensis and it was presumed that SIEBOLD\u27s dolphin is this species. But it is unknown if Hase dolphin is identical to TRUE\u27s Delphinus capensis which was caught in the coastal sea of the Cape of Good Hope

全頭類の研究-1 : ギンザメChimaera phantasmaの形態と雄の生殖器官について

The morphological characters and ecology of Chimaera phantasma and male\u27s reproductive organs were investigated. Specimens (115 males, 191 females) were collected at the Nagasaki Fish Market or caught by the authors themselves from September 1975 to October 1976. The variation of proportion percentages compared with body length is not remarkable and the growth curves of the male and female are indicated by the following formula: Male: W=0.1913L2.2269 Female:W=0.0376L2.6349 It was observed that the male\u27s condition factor increases with the increment of body length, but no seasonal variation of this factor could be observed. In females no variations of any kind were observed. The diet is basically formed by Crustacea, especially crabs, and teeth consist of three pairs of dental plates. The posterior clasper is trifurcated and has no remarkable appendices. External radii are rigid and the anterior clasper bears 8 serrations in a line. The pelvic girdle consists of right and left cartilages. Sexual maturity in males can be considered to be reached at a body length of 45 to 50cm.1975年9月から1976年10月にかけて長崎魚市に水揚げされたり,著者らが長崎県沿岸で採捕したギンザメ306個体(雄115個体,雌191個体)について,形態学的に,雄についはは生殖生態についても調査した。成長に伴う各部の外形プロポーションの割合はほぼ一様である。また,雌雄の成長式は次式で示された。雄:W(g)=0.1913L(cm)2.2269 雌:W(g)=0.0376L(cm)2.6349雄の肥満度は成長に伴い減少するのが観察された。歯は非常に強固な三対の歯板よりなり,主として底棲動物を捕食し,中でも小型のカニを最も多く捕食している。Posterior clasperは三叉し,先端は顕著な附属物はなく,external radiiは屈曲しない。Anterior clasperの内縁には一列に並んだ8個の棘があり,Pelvie girdleは左右二つに分離している。本種の雄は体長(No. 14) 45cmから50cmで成熟に達する