水中音に関する研究-5 : 南米産河イルカの水中鳴音について

The investigation on the underwater calls of three kinds of river dolphins, i.e., Amazon Dolphin (Inia geoffrensis), Buffeo negro (Sotalia fluviatilis) and La Plata river dolphin (Pontopolia blainvillei) that live in waters in South America was carried out. It has been considered that these dolphins made better use of the underwater calls than any other sea dolphins on account of their circumstances. However, conversely it was made clear that the underwater calls were lacking of the variety and frequencies, and moreover they were different in character from the underwater calls of the Ganges river dolphin (Platanista gangetica). For example, Buffeo negro did not emit the stratiformed sound, and both whistle and clicks of Amazon dolphin were limited in the range of low frequency. And also the frequency in their use of calls was exceedingly low. The underwater calls of La Plata river dolphin could not be recorded though the opportunity of observation was little.!?1. The underwater calls of the river dolphins in South America (Buffeo negro and Amazon dolphin) were recorded in natural environment and analys ed in comparison with the sea dolphin and the Ganges river dolphin. 2. Clear difference between the Buffeo negro and the Amazon river dolphin was obtained and further the underwater calls of these dolphins were different from that of the sea dolphins and the Ganges river dolphin. 3. For Buffeo negro, the stratiformed sound was not emitted. The frequency of whistle was higher than that of Amazon dolphin and clicks also showed the same tendency. 4. The frequency in use of calls was lower compared with any other kinds of dolphins

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"

Peripheral Glutamate Receptors Are Required for Hyperalgesia Induced by Capsaicin

Transient receptor potential vanilloid1 (TRPV1) and glutamate receptors (GluRs) are located in small diameter primary afferent neurons (nociceptors), and it was speculated that glutamate released in the peripheral tissue in response to activation of TRPV1 might activate nociceptors retrogradely. But, it was not clear which types of GluRs are functioning in the nociceptive sensory transmission. In the present study, we examined the c-Fos expression in spinal cord dorsal horn following injection of drugs associated with glutamate receptors with/without capsaicin into the hindpaw. The subcutaneous injection of capsaicin or glutamate remarkably evoked c-Fos expression in ipsilateral sides of spinal cord dorsal horn. This capsaicin evoked increase of c-Fos expression was significantly prevented by concomitant administration of MK801, CNQX, and CPCCOEt. On the other hand, there were not any significant changes in coinjection of capsaicin and MCCG or MSOP. These results reveal that the activation of iGluRs and group I mGluR in peripheral afferent nerves play an important role in mechanisms whereby capsaicin evokes/maintains nociceptive responses

水中音に関する研究-5 : インダス河イルカPlatanista gangeticaの水中鳴音について

Recording of the underwater call and observation of the relative behaviour of the river dolphin (Platanista gangetica) living in the Indus River were carried out. All of the underwater calls emitted by this dolphin were clicks which were continuously emitted. This call was mainly used for echolocation and, when small fishes were thrown into the pond, it was observed that the repetition rate of clicks emitted by the dolphin searching for bait rapidly became higher. The repetition rate was 30-200/sec. (usually 40-100/sec.) The analyzed patterns were monotonous and the particularly strong frequency band was not constant.The clicks emitted by the Indus River Dolphin were very similar to the call of the dolphin living in the Ganges River, but the stratiformed sound, burst, twitter and whistle which the Ganges River Dolphin emitted were not observed with the Indus River Dolphin.!?1. The underwater calls of the Indus River Dolphin were recorded in Pakistan were compared with that of the Ganges River Dolphin of the same species. 2. This dolphin lives at deep places and sinuous places of the Indus River and is always emitting the calls. 3. The emitting interval of underwater calls almost constant all day. 4. All of the calls of the Indus River Dolphin are of the type of so-called "Clicks" and play an important role in echolocation. 5. The analyzed pattern of these calls are monotonous and no special strong frequency band is recognized. 6. The repetition rate is 30-200/sec. (usually 40-100/sec.). 7. Regarding that the Ganges River Dolphin was under the breeding condition, the clicks of the Indus River Dolphin and the Ganges River Dolphin may have no difference at all. 8. Other calls observed in the Ganges River Dolphin were not recognized in the Indus River Dolphin

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

オットセイ仔獣の発生音の個体差について

The calls of six northern fur seal pups, Callorhinus ursinus, transported from Robben Island to Mito Sea Paradise were analized. The calls of northern fur seal pups consist of a short one of a few-tenths of a second and a shriek type of 1-2 seconds or longer. They have frequency components which range from a few-tens Hertz to eight kilo-Hertz. Each call consists of a clear main peak frequency and a sub-main peak frequency. The call of each pup has a characteristic structure which hardly changes according to the physiological condition. It is considered that a mother seal distinguishes the call of the pup and uses it as the first clue to find her pup.ロベン島で捕獲され,三津シーパラダイスに搬入されたオットセイ仔獣6頭の発生音を解析した.オットセイ仔獣の発生音は1秒の数分の1の短いものと,1～2秒,時には数秒持続する大きなワメキ音で,数十Hzから8kHz以上にも達する周波数成分より成る.各発生音は顕著な主極大周波数と副極大周波数より成る.各仔獣の発生音は各々特徴的な構造を有し,発音時の生理的状態によって大きく変わることはない.母獣はこれらの発生音を識別して,自己の仔獣を発見する最初の手掛りとしていると考えられる

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

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