The Byssal Apparatus in the Pacific Mussel, Mytilus trossulus (Bivalvia, Mytilidae), from the Sea of Japan

2021 ◽  
Vol 48 (9) ◽  
pp. 1443-1451
Author(s):  
E. E. Vekhova
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroshi Ishida ◽  
Ryosuke S. Isono ◽  
Jun Kita ◽  
Yutaka W. Watanabe

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.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2863 ◽  
Author(s):  
Anton Chichvarkhin

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.


Author(s):  
Nina I. Grigoryeva

Исследована скорость роста культивируемых моллюсков подвесного выращивания в зал. Посьета (зал. Петра Великого, Японское море) за 1970–2011 гг. Приведены ростовые характеристики приморского гребешка (Mizuhopecten yessoensis (Jay, 1857)), тихоокеанской мидии (Mytilus trossulus Gould, 1850) и тихоокеанской (гигантской) устрицы (Crassostrea gigas (Thunberg, 1793)) в течение первых трех лет развития. Методами энтропийного анализа исследованы сроки достижения личинками и спатом определенных размеров. Выявлены временные интервалы и рассчитана вероятность наступления этих сроков. Обсуждается влияние техники культивирования на скорость роста. Ключевые слова: скорость роста, личинки, спат, приморский гребешок Mizuhopecten yessoensis, тихоокеанская мидия Mytilus trossulus, тихоокеанская устрица Crassostrea gigas, залив Посьета, Японское море. The growth rates of cultivated mollusks were studied in Possjet Bay (Peter the Great Bay, Sea of Japan) during 1970–2011. The growth characteristics were presented for the Yesso scallop (Mizuhopecten yessoensis (Jay, 1857)), the blue mussel (Mytilus trossulus Gould, 1850), and the Pacific (giant) oyster (Crassostrea gigas (Thunberg, 1793)) during the first three years of life. The average amount of time of the larvae and spat reaching certain sizes was determined using the method of entropy analysis. The time intervals were identified and the probability of these intervals to happen were also calculated. The influence of the cultivation techniques on the growth rate is discussed. Key words: growth rate, larvae, spat, Yesso scallop Mizuhopecten yessoensis, blue mussel Mytilus trossulus, Pacific oyster Crassostrea gigas, Possjet Bay, Sea of Japan.


1985 ◽  
Vol 7 (3) ◽  
pp. 379-387 ◽  
Author(s):  
A. G. Rodnikov ◽  
A. G. Gainanov ◽  
B. V. Yermakov ◽  
V. M. Kovylin ◽  
V. A. Seliverstov ◽  
...  

1989 ◽  
Vol 67 (9) ◽  
pp. 2169-2179 ◽  
Author(s):  
Danièle Carré ◽  
Claude Carré

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]


Sign in / Sign up

Export Citation Format

Share Document