Acquisition de cnidocystes et différenciation de pseudocolloblastes chez les larves et les adultes de deux cténophores du genre Haeckelia Carus, 1863

1989 ◽  
Vol 67 (9) ◽  
pp. 2169-2179 ◽  
Author(s):  
Danièle Carré ◽  
Claude Carré
Keyword(s):  
Mediterranean Sea ◽  
Sea Of Japan ◽  
Outer Layer ◽  
Glandular Cell ◽  
The Sea Of Japan ◽  
Unknown Type ◽  
The Pacific ◽  
New Type ◽  
The Mediterranean

The development of two species of cydippid Ctenophora, Haeckelia rubra and Haeckelia bimaculata, was studied to determine the origin and acquisition of exogenous cnidocysts in these two species, which lack colloblasts. A new type of cell, the pseudocolloblasts, is described. In H. rubra, the outer layer of the egg contains cnidocysts which are ingested by the larva after gastrulation; these cnidocysts make up the initial stock of exogenous cnidocysts that will allow the ctenophore to catch its first Cnidaria. In H. bimaculata, the outer layer of the egg is devoid of cnidocysts. The hatching larva has no cnidocysts either, but its tentacles are lined by an hitherto unknown type of glandular cell that we have named the pseudocolloblast. Pseudocolloblasts are composed of a secretory head bearing regularly interspaced, striated structures and an anchoring stalk. They eject their content progressively during successive phases of exocytosis. Pseudocolloblasts differ morphologically from real colloblasts, but they probably have the same function and they allow larvae of H. bimaculata to catch cnidarian larvae and thus acquire the exogenous cnidocysts present in postlarval and adult stages. Cnidocysts are identical in both species of Haeckelia in the Mediterranean Sea, consisting of macroisorhizas and microisorhizas in which the intracapsular filament has five circumferential pleats, a character typical of Narcomedusae. They differ in size from the cnidocysts found in H. rubra in the Pacific and in the Sea of Japan.[Journal translation]

scholarly journals Long-term ocean acidification trends in coastal waters around Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroshi Ishida ◽  
Ryosuke S. Isono ◽  
Jun Kita ◽  
Yutaka W. Watanabe
Keyword(s):  
Pacific Ocean ◽  
Ocean Acidification ◽  
Sea Of Japan ◽  
Ocean Current ◽  
The Sea Of Japan ◽  
Marginal Seas ◽  
The Pacific ◽  
Activity Measurements ◽  
The Pacific Ocean

AbstractThis study examines long-term ocean pH data to evaluate ocean acidification (OA) trends at two coastal research institutions located on the Sea of Japan and the Pacific Ocean. These laboratories are located away from the influences of large rivers and major industrial activity. Measurements were performed daily for the past 30 years (1980s–2010s). The average annual ocean pH for both sites showed generally negative trends. These trends were – 0.0032 and – 0.0068 year–1 (p < 0.001) at the Sea of Japan and Pacific Ocean sites, respectively. The trends were superimposed onto approximately 10-year oscillations, which appear to synchronize with the ocean current periodicity. At the Sea of Japan site, the ocean pH in the summer was higher, and the rate of OA was higher than during other seasons. Our results suggest that seasonality and ocean currents influence OA in the coastal areas of open oceans and can affect the coastal regions of marginal seas.

scholarly journals Henricia djakonovisp. nov. (Echinodermata, Echinasteridae): a new sea star species from the Sea of Japan

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2863 ◽  
Author(s):  
Anton Chichvarkhin
Keyword(s):  
New Species ◽  
Sea Of Japan ◽  
Common Species ◽  
Sympatric Species ◽  
Variable Number ◽  
The Other ◽  
The Sea Of Japan ◽  
Sea Star ◽  
The Pacific ◽  
Russian Waters

A new sea star species,H. djakonovisp.n., was discovered in Rudnaya Bay in the Sea of Japan. This is a sympatric species of the well-known and common speciesHenricia pseudoleviusculaDjakonov, 1958. Both species are similar in body size and proportions, shape of skeletal plates, and life coloration, which distinguishes them from the otherHenriciaspecies inhabiting the Sea of Japan. Nevertheless, these species can be distinguished by their abactinal spines: in both species, they are short and barrel-like, but the new species is the onlyHenriciaspecies in Russian waters of the Pacific that possesses such spines with a massive, smooth, bullet-like tip. The spines inH. pseudoleviusculaare crowned with a variable number of well-developed thorns. About half (<50%) of the abactinal pseudopaxillae in the new species are oval, not crescent-shaped as inH. pseudoleviuscula.

scholarly journals Further spreading of the non-indigenous bryozoan Celleporaria brunnea in the Mediterranean Sea: port to port morphological variations

2015 ◽  
Author(s):  
Jasmine Ferrario ◽  
Agnese Marchini ◽  
Martina Marić ◽  
Dan Minchin ◽  
Anna Occhipinti-Ambrogi
Keyword(s):  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Indigenous Species ◽  
Large Variability ◽  
Morphometric Characters ◽  
Morphological Variations ◽  
The North ◽  
Western Mediterranean Sea ◽  
The Pacific ◽  
The Mediterranean

The Pacific cheilostome bryozoan Celleporaria brunnea (Hincks, 1884), a non-indigenous species already known for the Mediterranean Sea, was recorded in 2013-2014 from nine Italian port localities (Genoa, Santa Margherita Ligure, La Spezia, Leghorn, Viareggio, Olbia, Porto Rotondo, Porto Torres and Castelsardo) in the North-western Mediterranean Sea; in 2014 it was also found for the first time in the Adriatic Sea, in the marina “Kornati”, Biograd na Moru (Croatia). In Italy, specimens of C. brunnea were found in 44 out of 105 samples (48% from harbour sites ad 52% from marinas). These data confirm and update the distribution of C. brunnea in the Mediterranean Sea, and provide evidence that recreational boating is a vector responsible for the successful spread of this species. Previous literature data have shown the existence of differences in orifice and interzooidal avicularia length and width among different localities of the invaded range of C. brunnea. Therefore, measurements of orifice and avicularia were assessed for respectively 30 zooids and 8 to 30 interzooidal avicularia for both Italian and Croatian localities, and compared with literature data, in order to verify the existence of differences in the populations of C. brunnea that could reflect the geographic pattern of its invasion range. Our data show high variability of orifice measures among and within localities: zooids with broader than long orifice coexisted with others displaying longer than broad orifice, or similar values for both length and width. The morphological variation of C. brunnea in these localities, and above all the large variability of samples within single localities or even within colonies poses questions on the reliability of such morphometric characters for inter and intraspecific evaluations.

Geotraverse across the Sikhote Alin ? The Sea of Japan ? The Honshu Island ? The Pacific

1985 ◽  
Vol 7 (3) ◽  
pp. 379-387 ◽  
Author(s):  
A. G. Rodnikov ◽  
A. G. Gainanov ◽  
B. V. Yermakov ◽  
V. M. Kovylin ◽  
V. A. Seliverstov ◽  
...  
Keyword(s):  
Sea Of Japan ◽  
The Sea Of Japan ◽  
Sikhote Alin ◽  
The Pacific ◽  
Honshu Island

scholarly journals Negotiating a Postmemory Dichotomy: Nostalgia and Aversion in Malta

Politeja ◽  
2020 ◽  
Vol 17 (2(65)) ◽  
pp. 239-256
Author(s):  
George Cassar ◽  
Marie Avellino
Keyword(s):  
Mediterranean Sea ◽  
Social Reality ◽  
Tourism Industry ◽  
The Other ◽  
Great Effort ◽  
Service Personnel ◽  
Second Home ◽  
Other Hand ◽  
New Type ◽  
The Mediterranean

The island of Malta has served as a strategic colony since the dawn of history. Since Phoenician and Roman times, the island has been an important base in the middle of the Mediterranean Sea. Its last colonisers, the British, spent about 180 years using the islands for their imperial needs. The official closing of the British base on 31 March 1979 heralded a new economic and social reality supposedly unhampered by the exigencies of foreigners. Two major post-memory reactions kicked in – nostalgia and aversion to ex-colonial life. The postcolonial Maltese generations exhibit a range of reactions oscillating between love and hate for the British. On the other hand, British ex-service personnel and their families have continued to feel an affinity with the island base which they had come to acknowledge as a second home. This allows for a new type of relationship between the Maltese people and their British visitors where issues of colonial post-memory are negotiated. These are seen at their best in the local tourism industry. Malta woos British tourists and goes to great effort to attract them. It uses to its advantage the colonial affinity to create an attractive destination for the British which benefits the locals and the Maltese economy. In Malta post-memory has evolved in line with necessity and expediency, where animosity, though manifestly tangible, has gradually morphed into a rather benign residue in the collective reaction to the colonial past.

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