issued from : J.M. Bradford in N.Z. J. Mar. Freshw. Res., 1976, 10 (1). [p.174-175, Figs.11,12]. Female (from Japan): 1a, habitus (dorsal view); 1b, idem (lateral view); 1c-e, P5; 2a-c, genital segment (dorsal view); 2d-f, idem (lateral view).
issued from : J.M. Bradford in N.Z. J. Mar. Freshw. Res., 1976, 10 (1). [p.175, Fig.13]. Male (from japan): a, habitus (dorsal view); b, idem (lateral view); c, posterior surface of P5; d, terminal segment of left P5.
issued from : O. Tanaka in Publs Seto Mar. Biol. Lab., 1965, XII (5). [p.388, Fig.244]. As Acartia clausi. Female: a, habitus (dorsal); b, last thoracic segment and urosome (left lateral side); c, proximal portion of A1; d, P5. Nota: Rostral filament absent. Abdomen 3-segmented, contained 3.3 times in the length of cephalothorax The abdomen segments and furca are in the proportional lengths as 41:24:14:21 = 100. Thorax segments and genital segment covered with fine hairs. P5: in the middle segment squarish in shape; the claw-like spine swollen at the basal portion and spinulose on each side; the outer marginal seta longer than the claw. Genital and 2nd abdominal segments fringed with fine teeth on the distal margin
Male: P5. Nota: Lateral corner of last thoracic segment furnished with short hairs. Abdomen contained 3.1 times in the length of cephalothorax. The abdominal segments and furca are in the proportional lengths as 15:30:19:7:11:18 = 100. 2nd to 4th fringed with minute spinules on the dorsal distal margin.
issued from : C.-j. Shen & S.-o. Bai in Acta Zool. sin., 1956, 8 (2). [Pl.VII, Figs.49-51]. As Acartia clausi. Male (from Chefoo): 49, habitus (dorsal); 50, P5.
Nota: In the specimens, the 1st and 2nd abdominal segments of the female and the 2-4 abdominal segments of the male are without spinules on their posterior margins.
issued from : H. Ueda in J. Oceanogr. Soc. Japan, 1986, 42. [p.136, Fig.2]. Comparative aspects between A. omorii, A. hudsonica and A. clausi. A. omorii (from Maizuru Bay, Japan): Female: A-B, urosome (dorsal and lateral, respectively);. Male: C, P5 (posterior view); D-E, 3rd segment of right P5 (other specimens).
A. hudsonica (from Maizuru): Female: F-G, urosome (dorsal and lateral); H, P5 (posterior view); I-J, 3rd segment of right P5 (other specimens).
A. clausi (after Bradford, 1976): Female: K-L, genital segment (dorsal and lateral, respectively).
issued from : H. Ueda in J. Oceanogr. Soc. Japan, 1986, 42. [p.136, Table 1]. Comparative list of distinctive characters of A. omorii and A. hudsonica, after Bradford, 1976.
issued from : T. Mori in The pelagic Copepoda from the neighbouring waters of Japan, 1937 (2nd edit., 1964). [Pl.50, Figs.8-13]. As Acartia clausi. Female: 8, habitus (dorsal); 10, P5; 13, forehead (ventral). Nota: Rostral filaments absent. Urosomal segments with fine spinules on the posterior margins. A1 with without spines on the proximal segments, and extend about the end of the genital segment. The middle segment of P5 is nearly as long as its width; the claw-like terminal segment is stout; the marginal seta is much longer than the terminal segment.
Male: 9, habitus (dorsal); 11, P5; 12, right A1 (distal portion). Nota: Right leg of P5 consists of 4 segments; the inner margin of the 2nd segment has a blunt process of the distal portion; the 3rd segment also has a blunt process on the inner margin. Left leg of P5 consists of 3 segments; the terminal segment has a vermiform appendage and 1 spine.
issued from : Y.-S. Kang & S.-S. Lee in Bull. Korean Fish. Soc., 1990, 23 (5). [p.380, Fig.1]. Female (from Korea): D, habitus (dorsal); E, 1st and 2nd urosomal segments (dorsal); F, genital segment (lateral).
Male: A, habitus (dorsal); B, P5; C, inner lobe of 3rd segment of right P5.
issued from : R.-M. Bathélémy in J. Mar. Biol. Ass. U.K., 1999, 79. [p.860, Fig.3, E, F]. Scanning electon miccrograph. Female (from Maizuru Bay, Japan): E, genital double-somite (ventral); F, genital area (external ventral view); Note the two lengthened genital slits (small arrows) each protected by a lamellar flap (arrowheads) and the medioventral position of genital area. Scale bars: 0.030 mm (E, F). Symbol: * = fixation of the spermatophore.
issued from : L. Seuront in J. Plankton Res., 2005, 27 (12). [p.1303, Table I]. Comparisons of distinctive characters of Acartia species closely related to each other.
issued from : L. Seuront in J. Plankton Res., 2005, 27 (12). [p.1304, Table II]. Prosome length and body proportions of Acartia omorii males and females sampled in the southern bight of the North Sea (France) and the type locality (Tokyo Bay, Japan) and Acartia clausi males and females sampled in the southern bigght of the North Sea (France).
issued from : L. Seuront in J. Plankton Res., 2005, 27 (12). [p.1304, Table III]. Allometric relationships obtained between prosome length and different morphometric ratios for Acartia omorii adult males and females sampled in the southern bight of the North Sea (France) and in the type locality (Tokyo Bay, Japan).
Issued from : R. Hirota & S. Uno in Bull. Plankton Soc. Japan, 1977, 24 (2). [p.80, Fig.3, C, D]. Pelagic eggs of Acartia clausi (= A. omorii) from vicinity of Amakusa-Matsushima (western Kyushu, Japan).
Issued from : M. Chihara & M. Murano in An Illustrated Guide to Marine Plankton in Japan, 1997. [p.674, Pl. 16, fig.6 a-g]. Female: a, habitus (dorsal); b, last thoracic segment and urosome (dorsal); c, same (lateral, right side); d, P5.
Male: e, habitus (dorsal); f, last thoracic segment and urosome (dorsal); g, P5 Nota: numbers show caracteristics of this species to compare with A. hudsonica.
Issued from : H.Y. Soh & H.-L. Suh in J. Plankton Res., 2000, 22 (2). [p.332, Table I]. Distinctive characters of Acartia omorii. a: referred from Ueda (1986). Nota: Compare the distinctive characters with the closely related species A. hongi, A. hudsonica in the coastal waters of Korea, and A. bifilosa.
issued from : H. Ueda in J. Oceanogr. Soc. Japan, 1986, 42. [p.136, Fig.1]. Distribution of A. omorii and A. hudsonica in Japanese inlet and cosatal waters.
issued from : S.-I. Uye in J. Exp. Mar. Biol. Ecol., 1982, 57. [p.65, Fig.10]. Generation of Acartia clausi ( = A. omorii) estomated from adult female cephalothorax length and relative abundance of CI and CIV as a percentage of all copepodites during the period from December, 1977 to September, 1978 in Onagawa Bay (Japan). G: numero of the generation.
Nota: The life cycle is continuous throughout the year, while the fluctuation in population abundance is remarkable. The number of generations during the year is six. If food is in excess, the females lay eggs at a physiologically maximum rate which is controlled by temperature (See Uye, 1981). Unless strong upwelling occurs, most eggs after spawning sink to the bottom and are inhibited from hatching for some period until being washed free from the bottom by wave action or tidal current (see Landry, 1978). Once eggs can hatch into nauplii, the larvae follow a characteristic growth mode, i.e. isochronal development (see Miller & al., 1977).
issued from : S.-I. Uye in J. Exp. Mar. Biol. Ecol., 1982, 57. [p.60, Fig.3]. Seasonal change in water temperature at depths of 1, 5, 10 m and near the bottom, and salinity at depths of 1 and 10 m at inermost part of Onagawa Bay (38°25'N, 141°30'E)
issued from : S.-I. Uye in J. Exp. Mar. Biol. Ecol., 1982, 57. [p.66, Table I]. Estimated generation lengths from field data compared with lengths predicted from temperature during development. a: Prediction is made assuming temperature is 20°C, since the development rate does not increase above 20°C. Uye (1980) has previously investigated the postembryonic development at various temperatures with excess food in the laboratory and found that the time taken from egg-laying to adult stage is 17.9 times duration of the embryo which can be expressed by the beleradek equation.
issued from : S.-I. Uye in Bull. Plankton Soc. Japan, 1980, 27 (1). [p.13, Fig.2]. Post-embryonic development of Acartia clausi (= A. omorii at 7.3, 11.2, 14.5, 16.4 and 20.3°C, cultured with excess food. Each point is the time required for 50 % of individuals molting into each stage. Straight lines are fitted by the least squares to all points except one entering into N III.
Issued from : D.G. Lacuna & S.-I. Uye in J. Plankton Res., 2001, 23 (2). [p.152, Fig.9]. Survival of some selected developmental stages of Acartia omorii exposed at different UVB doses under simultaneous irradiation of enhanced Photosynthetically Active Radiation (PAR: 400-700 nm). Vertical line denotes standard deviation. Animals collected at Ondo (Kune, Japan).
Nota: no deleterious effect was inducede by UVA (320-400 nm) or PAR (400-700 nm), but UVB inflicted a more damaging effect with increasing UVB dose. Among various life stages, eggs, particularly freshly-spawned ones (< 2 h old), were most susceptible, and adult females least susceptible. The feeding and egg production of adult females were not sibhificantly reduced until the UVB dose was elevated to 15.0 kJ per m2.
Issued from : D.G. Lacuna & S.-I. Uye in J. Plankton Res., 2001, 23 (2). [p.152, Fig.10]. Hatching success of Acartia omorii eggs exposed at different solar UVB doses. Results from the two laboratory experiments using one UV plus one fluorescent lamp, and two UV plus 15 fluorecent lamps, are also plotted for comparison. Vertical line denotes standard deviation.
Nota: Experiment using solar UVB demonstrated that present-day levels of solar UVB radiation caused reduced hatching success of A. omorii eggs. In the habitat of A. omorii, however, due to high attenuation properties of the water, the solar UVB radiation may affect only young developmental stages distributed near the sea surface.
Issued from : H. Bi, K.A. Rose & M.C. Benfield in Mar. Ecol. Prog. Ser., 2011, 427. [p.157, Table 5]. Instantaneous mortality rates (individuals per day) from litterature.
Issued from : J.-H. Kang in Ocean Sci. J., 2011, 46 (4). [p.228, Fig.5] Abundance-temperature-salinity diagram of A. omorii observed in the seaports from Korea during 3 years (2007-2009).
Issued from : J.-H. Kang in Ocean Sci. J., 2011, 46 (4). [p.229, Fig.6] Abundance-total suspended solid-chlorophyll-a diagram of A. omorii observed in the seaports from Korea during 3 years (2007-2009).
Issued from : J.-H. Kang in Ocean Sci. J., 2011, 46 (4). [p.230, Fig.7] Abundance-dissolved oxygen-chlorophyll-a diagram of A. omorii observed in the seaports from Korea during 3 years (2007-2009).
Issued from : T. Ayukai in Mar. Biol., 1987, 94. [p.580, Fig.1]. As A. clausi (= A. omorii. Relationship between ingestion rate and defecation rate of adult females feeding on each of three algal species, different by the equivalent spherical diameter (ESD). The fecal pellet measurements in determining the ingestion rate of copepods has been discussed (Marshall & Orr, 1955; Gaudy, 1974; Reeve & Walter, 1977), but, Ayukai & Nishizawa (1986) reported that the volume of cells ingested by Calanus pacificus was directly correlated with that of their fecal pellets, and that the ingestion rate of cells was indirectly calculated by determining the defecation rate. In Table 1 the ESD and volume respectively of the three species of algae offered to females are : Dunaliella tertiolecta: 5,6 µm, 91 ± 24 µm; Thalassiosira decipiens 13,4 µm, 1270 ± 180 µm3; Thalassiosira nordenskioldii 17.7 µm, 2880 ± 390 µm3. The adult females Acartia clausi (= A. omorii) are sampled in Onagawa Bay (northeast mainland of Japan).
Issued from : T. Ayukai in Mar. Biol., 1987, 94. [p.581, Fig.2]. As A. clausi (= A. omorii). Relationship between cell concentration and ingestion rate on cells by adult females feeding on each three algal species.
Issued from : T. Ayukai in Mar. Biol., 1987, 94. [p.582, Fig.3 & Table 7]. As A. clausi (= A. omorii. Relationship between bead concentration and ratio of ingested beads to ingested cells for adult females feeding on each three algal species in mixtures with polystyrene beads (15.7 µm diameter).
Issued from : T. Ayukai in Mar. Biol., 1987, 94. [p.585, Table 6]. As A. clausi (= Acartia omorii). Filtering rates of adult females feeding on each of three algae, singly or in mixture with polystyrene beads.
Issued from : T. Ayukai in Mar. Biol., 1987, 94. [p.583, Table 3]. As A. clausi (= Acartia omorii). Ingestion rates of adult females feeding on Thalassiosira decipiens singly (13.4 µm diameter) or in mixtures with polystyrene beads (15.7 µm diameter).
Issued from : T. Ayukai in Mar. Biol., 1987, 94. [p.584, Table 5]. As A. clausi (= Acartia omorii). Ingestion rates of juveniles and adults feeding on Thalassiosira decipiens singly (13.4 µm diameter) or in mixture with polystyrene beads (15.7 µm diameter).
The present study shows that juvenile copepods discriminate between beads and cells more succesfully than adults and suggests that the presence of beads rarely affects the ingestion rate of juvenile on cells. Juvenile copepods have an advantage in maximizing the net energy gain over adults, especiially when suspended particulate matter consists mainly of detritus and nanoplankton dominates over microplankton. Adversely, adult copepods need tactical feeding behaviors under such conditions; the predatory feeding and the utilisation of large particles such as fecal pellets are the possible ones (Ayukai, 1986). [[also, see the vertical distribution different between juvenile stages and adults and the structure of mouthpart appendages (Nival & Nival, 1976: Particle retention efficiencies of an herbivorous copepod, A. clausi, adult and copepodite stages: effects on grazing). CR.]]. When mixtures of beads and Thalassiosira weissflogii were offered to stages N III to C II (Fernandez, 1979) and C IV to VI (Huntley & al., 1983) of Calanus pacificus, bead interference was observed only in individuals in the latter stages. Similarly, bead interference was more probable for adult female A. omorii than for the juveniles (Table 5). These may result from small copepods having a higher ability to perceive cells individually than large ones. This notion may be supported by a finding that T. weissflogii are individually perceived by small Eucalanus species, but poorly perceived by large ones such as E. elongatus (Price & Paffenhöfer, 1986). In a mixture of beads and T. decipiens, A. omorii with hihgh food requirements tend to ingest more beads than those with low food requirements, i.e. starved adult females vs well fed ones, adult females vs adult males and spawning females vs post-spawning females (Table 5). Three possibilies have been considerd: - beads elicit some response from copepods with high food requirements, though beads offered singly were ingested by neither starved nor well fed adult female. - Copepods with high food requirements respond to cells at a longer distance than those with low food requirements. A chance of bead ingestion may increase with increasing response distance. These explanations are based on the assumption that the former have a higher ability to perceive cells than the latter. - Copepods with high food requirements devote more time collecting cells pasively, and reluctantly ingest more beads than those with low food requirements. It is necessary to test these possibilities.
Issued from : T. Ayukai in Mar. Biol., 1987, 94. [p.584, Table 4]. As A. clausi (= Acartia omorii). Ingestion rates of adult females feeding on Dunaliella tertiolecta (ESD = 5.6 µm diameter) singly or in mixtures with polystyrene beads (15.7 diameter).
Female selectively ingested D. tertiolecta in mixtures with beads, the volume of the later being 20 times larger than of the former. The simplest model of the apparent size-selective feeding of copepods (Boyd, 1976; MLam & Frost, 1976; Friedman, 1976) cannot explain this result.. Copepods have numerous chemoreceptors on the moth part (Friedman & Strickler, 1975; Friedman, 1980). Direct cinematographic observations have revealed that copepods detect the chemical properties from cells at a distance (Alcaraz & al., 1980; Paffenhöfer & al., 1982). Copepods capture individually perceived cells in an active mode and poorly perceived ones in a passive mode (Price & al., 1983). - In an active mode, copepods bring individual cells to the mouthpart by maneuvering the movements of feeding appendages, capture the water parcel with a cell inside and then remove the water by squeezing it out (Koehl & Strickler, 1981; Strickler, 1982) - In a passive mode, copepods accumulate cells near the mouthpart by continuous low amplitude vibration of the 2nd maxillae (Mx2) and ingest these cells somewhat inefficienlly (Price & al., 1983) The pattern of the movements of feeding appendages is different between A. omorii and other calanoids (Conover, 1956; Gauld, 1966). Little is known as to whether or not A. omorii capture differently perceived cells in different feeding modes. However, the results of experiments are well explained by assuming that the female A. omorii ingest Thalassiosira nordenskioldii (ESD =17.7 µm diameter) in a active mode, Dunaliella tertiolecta (ESD = 5.6 µm diameter) in a passive mode and T. decipiens (ESD = 13.4 µm diameter) in both modes. The presence of beads (15.7 µm diameter) did not affect the ingestion rate of adult female A. omorii on T. nordenskioldii, and the more cells female A. omorii ingested, the higher the ingestion rate on beads (Table 2). The ratio of ingested beads to ingested cells was linearly correlated with bead concentration (Table 7). These results suggest that that the problem of the bead ingestion is related to the probability of the existence of beads in the water parcel containing a cell and the probability increases with increasing bead concentration. If so, it may be understood that the ingestion rate on beads continued to increase up to about 10000 beads ml-1, whereas the ingestion rate on cells became satured (Table 2, 3). In the present study, beads offered singly were not ingested by adult female. This result suggests that beads are ingested by 'chance' in feeding bouts of copepods on cells. Paffenhöfer & Van Sant (1985) reached the similar conclusion that the bead ingestion is a function of the cell ingestion.
Issued from : T. Ayukai in Mar. Biol., 1987, 94. [p.582, Table 2A. clausi (= Acartia omorii). Ingestion rates of adult females feeding on Thalassiosira nordenskioldii singly or in mixtures with polystyrene beads. T. nordenskioldii (ESD = 17.7 µm diameter; volume = 2880 ± 390 µm3; beads (ESD = 15.7 µm diameter).
China Seas (Yellow Sea, East China Sea, South China Sea, Korea (NW, S & E, Geumo Is., Gwangyang Bay), Korea Strait, Ilkwang Bay, Japan (Tokyo Bay, Izu, Ondo, Toyama Bay, off Sanriku, Fukuyama Harbor, Honshu: Maizuru Bay, Suruga Bay, Seto Inland Sea, Ariake Sea, Amakusa-Matsushima, Tanabe Bay, south estuaries, Honshu: Onagawa Bay, Gokasko Bay,, Okkirai Bay, Kyushu: Shijiki Bay, ? Omura Bay, Hokkaido), Taiwan, Kuroshio Current, California (Tomales Bay), Chile, SW North Sea (Calais Harbour)
épipélagique. Transport au Chili et en Californie (San Francisco) sans doute dans les ballasts des navires (Hirakawa, 1988, p.357), comme dans le port de Dunkerque (France). Voir aussi les remarques en anglais
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Razouls C., Desreumaux N., Kouwenberg J. et de Bovée F., 2005-2020. - Biodiversité des Copépodes planctoniques marins (morphologie, répartition géographique et données biologiques). Sorbonne Université, CNRS. Disponible sur http://copepodes.obs-banyuls.fr [Accédé le 01 décembre 2020]