A new locality is found from Japan on the crab, Lithodes aequispina Benedict (1894). This crab has been taken from waters, 450〜740m in depth, off Shioyazaki, Fukushima Prefecture. The crab in question is characterized by the rostrum, which is armed with 9 (Fig. 1B) or 10 spines. Sometimes 3 spines are found on the dorsal surface of the rostrum, when the spines of the rostrum enumerate 10 spines in total number. The carapace furnished with 111〜161 acute short spines (Fig. 1A). This spines have a trend decreasing in number with growth. An individual, 85mm in carapace length, bears 161 spines, that, 112mm long, has 136 spines, and that, 160mm long, has 111 ones. In adult form, the width of the carapace is larger than the length of the carapace. This inclination seems to be a little more salient in male than in female as shown in the Table 1. The egg of this crab is comparatively lager, measuring ca. 1.1mm in longer diameter, ca. 0.9mm in shorter one. Fishery of this crab, in Iwaki city, Fukushima Pref., takes place during the months from December to September. Vigorous season ranges from January to March. Some females taken in March are found bearing eggs beneath abdomen. This crab is fished by using a cage about 45cm and 120cm in diameter of the mouth and the bottom respectively, about 58cm in height. Some fishes, such as scomber, saury, sardine, anchovy, and others are used for the bait.

抄録全体を表示

Previously the author described four species of Cumacea from the Japanese southern coast of the Sea of Japan as new to science: Leucon simanensis (Gamo, 1962), which was obtained from the materials of cumaceans collected by Dr. TAIJI KIKUCHI of the Amakusa Marine Biological Station of the Kyusyu University during his ecological survey of Shinji Lake and Nakanoumi Lake in Tottori Prefecture, and Bodotria biplicata, Pseudoleucon japonicus, and Schizotrema sakaii (Gamo, 1964), which were found in the collection made by the author at Sado Island from 22 to 28 October 1962. The present short report deals with the further result of the examination of the samples of the two collections. [table]

抄録全体を表示

The author reviewed his former studies on the minute structures of fossils in Japan. Minute structures of carapace in some recent and fossil crabs are investigated in this paper, based upon the photographs of electron-microscope. Carcinoplax longimanus-the recent species shows the horizontal and inclined structures in the section of carapace, in which a canal system may be found. The diameter of the canals is ranging from 1 to 3 microns. Cancer minutoserratus from the Tatsunokuchi formation in Sendai shows the assemblages of polygons with linear structure, in the surface of carapace. Carcinoplax prisca from the Miocene formation of Miyazaki Prefecture shows sub-rounded polygonal assemblages on the surface of the carapace. Notopocorystes stokesii from the Cretaceous Greensand of Cambridge shows rounded polygonal assemblages on the surface of carapace. It seems that fossil crabs have the tendency of orthogenetic evolution from the rounded polygonal assemblages in the minute structure of the surface of carapace to the angular ones, but the mutual relation of the minute structure of carapace in the recent species between the surface and the section is not yet clear. In future, it is most necessary to observe the sections of carapace of fossil crabs by electron microscope, and subsequently to study the relation between micro-structures of inorganic materials of carapace and organic materials in fossil crabs.

抄録全体を表示

本報告において筆者はアナジャコ類の3新種を記載した。即ち,Fam. Axiidae Calocaris(Calastacus) mimasensis sp. nov. Fam. Upogebiidae Upogebia(Upogebia) acanthochela sp. nov. Fam. Callianassidae Callianassa(Callichirus) nakasonei sp. nov.第1の種は筆者自ら土佐湾御畳瀬の底曳漁船の残滓から採集したもので,日本からは最初に記載される属,第2の種類は東支那海から長崎市西海区水産試験場の山下秀夫氏によって採集されたもの,第3種は沖縄本島に近い渡名喜島の砂浜にて九大大学院学生,仲宗根幸男氏によって採集されたものである。これら3種の模式標本は,九大農学部動物学教室に保管されている。種の特徴の概略は下記の通りである。1.Calocaris(Calastacus) mimasensis sp. nov.体長は30mm,額角は細長く,その両側に2小歯がある。甲背の前半部には正中線とその両側に各2条の小歯をもった隆起線が走っている。第1脚は左右ほぼ相称で,その外面は毛に被われ,掌節の上縁に3棘がある。尾脚の外肢に小葉があること,甲背の後半部の後縁近くに正中線上の隆起があること,触角棘が長いことなどからCalocarisと認められる。日本近海からは初めて知られた属で,高知市御畳瀬の底曳漁船で得られた。2.Upogebia(Upogebia) acanthochela sp. nov.体長27mmに達する。第1脚の掌節の上縁には1列の,叉内面には3列の極めて顕著な棘が列生している。額角は良く発達していて,その下縁には2〜3棘がある。甲殻前縁の左右の突起は極めて短かい。甲殻前側縁には7〜8個の小歯があり,頸溝の後方には1対の顕著な棘がある。長崎市の西海区水産試験所の山下秀夫氏によって,東支那海からドレッジによって採集された。3.Callianassa(Callichirus) nakasonei sp. nov.体長39mm。尾脚の外肢は良く発達していて,槍形の内股よりも長く伸びている。額角は鋭い棘状,又甲殻前縁の両側には額角と同様な鋭い棘がみられる。第1脚は左右不相称で,その大鉗の長節は下縁に沿って4個の粒状突起が並ぶ。叉座節は上縁,下縁ともに滑らかである。第3顎脚の前節は内縁が良く突出している。大学院学生の仲宗根幸男氏が沖縄本島に近い渡名喜島の砂浜で採集したものをいただいた。

抄録全体を表示

This paper deals with the sacculinization occurred in a male of the pea crab, Pinnetheres sinensis Shen. The specimen was found living commensally within the mantle cavity of the common bivalved shell, Mytilus edulis Linne, obtained on the coast of Tokyo Bay in October, 1964. The body of the adult normal male of Pinnotheres sinensis is rather flat and solid, much smaller than the normal female which has the grobular and soft-shelled body. Even in the largest male, the length of carapace is less than one half that of the fully grown female. In the male, the chela is somewhat thickset compared with that of the female and its propodus furnished with 10-13 setae near the distal end of the anterior border. In second and third pairs of the male ambulatory legs, the carapus is crossed by an oblique row of long feathered hairs, and the propodus fringed with same hairs along the anterior borders. The dactylus of all pairs is claw-shaped and shorter than the propodus. In the female, the dactylus of the last ambulatory leg is rod-shaped and longer than the propodus, furnished with longish hairs along the inner border, with short hairs around the whole surface in distal half. The width of the male abdomen is much narrower than that of the female-about one fifth the length of the carapace, and its sixth abdominal segment has a hook-shaped process on the lateral margin. Of the two pairs of male pleopods, the posterior one has a short flatty exopodite. Of the four pairs of female pleopods, the posterior two are uniramous and has no exopodite (Fig. 1). The external morphological modifications are seen in the male, by sacculinization, as shown in the following: a) The size of the body becomes comparatively larger than in the normal male, and its exoskeleton becomes softend as in the female body (P1. VI). B) The chela becomes somewhat slender and the setae on the propodus are replaced by soft longish hairs, covering the distal surface of both fingers (Fig. 2, 3). C) The long feathered hairs seen on the second and third ambulatory legs are worn out and the dactylus of the fourth ambulatory leg is longer than the propodus, furnished with long hairs as seen in the female (Fig. 2, 1). D) The width of abdomen is broadened; the lateral margin of the sixth segment becomes entire and with marginal hairs (Fig. 3). E) No change of form seems to occur in the first pleopod except for its tip. The carified bridge at the foot of the first pleopod is rudimented. The exopodite of the second pleopod is well developed and covered with long soft hairs. No pleopod is seen in the third abdominal segment, while in the fourth abdominal segment, a uniramous appendage is seen on the right side (Fig. 3 and 4). The internal morphological modifications are seen in testis and midgut gland. These organs are entirely rudimented, being only represented by withered cells. The roots of the parasite glowing thickly around the vas deferens, the midgut gland, the anterior portion of intestine, and the thoracic ganglion. In vas deferens, however, sperms and spermatophores are still seen filling the duct. The penetration of roots of the parasite into the thoracic ganglion has already been investigated by the previous authors (MATSUMOTO K. (1952) and HOSHINO K. (1962)), so the author's present investigation is confined to that of the vas deferens.

抄録全体を表示

Two megalopa larvae of Percnon planissimum (Herbst) were obtained on the coasts of Hayama, Sagami Bay (Sep., 1964) and Hachijo Island (Aug., 1966), and reared in the aquarium until they reach the first crab stage. Megalopa stage: (The carapace 5mm in length, 3.8mm in width.) The carapace has no dorsal spine. The dorsal surface of carapace is thickly covered with a fine tomentum. The rostrum is horizontally projecting forwards. The postero-lateral portion of the carapace is somewhat swollen. The flagellum of second antenna has ten segments and its distal segment is furnished with a short hair and two long ones. In the third maxilliped the endopodite has the distal five segments setose and its exopodite one-segmeted and about half as long as the ishium. The dactylus of the fourth ambulatory legs is provided with two long feelers at the distal end. The second to fifth abdominal segments are respectively provided with a pair of biramous pleopods. There are 33〜44 swimming hairs on the lateral margin of the exopodite of pleopods. The small hooks are growing along the inner margin of the endopodite of pleopods. The sixth abdominal segment is provided with a pair of uropods, which are rather smaller in size, bearing 25〜26 swimming hairs on the lateral margin. The number of segments of exopodite and that of swimming hairs are compared with those of the megalopa of Plagusia dentipes and Plagusia depressa tuberculata in Table I. First crab-stage: (The carapace 5.5mm in length, 5mm in width.) The aspect of the body approaches that of the adult crab. The carapace is slightly larger than that of the megalopa. In the first crab-stage, the abdomen has seven distinct segments, while in the next stage (carapace 8mm in length, and 8mm in width), the third to fifth abdominal segments are almost coalescent with each other as in the adult crab.

抄録全体を表示

1.伊豆大島及びその付近より神津島に至る水域のカニについて,1954年より1965年までの調査結果から16科78属130種を同定し,本水域における分布相について論及した。2.同定されたカニの系統別構成は次の通りである。I.インド太平洋種44,II.インド洋特有種36,III.熱帯太平洋種13,IV.極東固有種7,V.日本固有種27,VI.北部太平洋(寒流系)種1,VII.汎世界的分布種2。I〜IIIは熱帯系種で合計93,IV〜Vは温帯及び亜熱帯系種で34,この構成は日本全土の分布相にほぼ似ている。3.本報告が新しい北限地となる熱帯系種は22で,この中には小笠原,北大東島,沖縄が従来の北限地とされていた各1種が含まれている。4.本水域でのカニ類の分布相は八丈島から相模湾への移行型を示すが,黒潮本流の強い影響を受けて,その地理的位置よりも南の分布相を示し,ことに大島汀線帯のカニについて,それが著しいことを確認した。ただし,この分布相は,黒潮の強勢な夏期を中心とした季節的なものであろうと考えられる。5.安定した砂泥底質の海浜を欠き,淡水系に乏しい大島から得られた3種のSand Crab-Ocypoda stimpsoni, O.cordimana,Scopimera globosa;2種のEsturine crab-Eriocheir japonicus, Sesarma(Holometopus) haematocheir:1種のFresh water crab-Potamom(Geothelphusa) dehaaniについてのべ,波浮港内のカニの生活についても言及した。6.稀少種のうち,Lasiodromia coppingeni unidentata, Achaeopsis rostrata,Platymaja bartschi, Ovalipes iridescens, Charybdis orientalis, Lybia tessellata, Geograpsus crinipesの7種についてのべた。

抄録全体を表示