Changes in biochemical composition in the red grouper, Epinephelus akaara (Temminck and Schlegel), and the black sea bream, Mylio macrocephalus (Basilewsky), during hypoxic exposure

The proximate biochemical composition and metabolic rates of ctenophores Mnemiopsis leidyi and Beroe ovata from the Black Sea were examined with respect to starvation conditions. Although organic matter content in B. ovata was two times higher than that of M. leidyi (2.51 ±0.53 and 1.14 ±0.17 mg g-1 of wet weight, respectively), these species did not significantly differ in their biochemical composition. In both species protein formed about 80% of the total organic matter, lipids amounted to about 10%. Carbohydrate and amino acids measured separately made up less than 6.5% of the total organic matter. Under experimental starvation (18 days at 16—18°C for B. ovata and 8 days at 12.4°C for M. leidyi), wet weights of both ctenophore species were reduced by 9.4% and 9.3% d-1, respectively. The rate of organic matter decrease was nearly two times lower than that of wet weight being on average 5.9% d-1 in M. leidyi and 5.5% d-1 in B. ovata. There was no trend in percentage of the four major biochemical categories with starvation time. The glycogen content in polysaccharides reached maximum values in freshly collected ctenophores (76.0 ±7.9% in B. ovata, and 86.6% in M. leidyi), but it was reduced substantially (34.4 ±2.7% in B. ovata and 18.3—28.8% in M. leidyi) with starvation. Monosaccharide content, expressed as a percentage of total carbohydrate, decreased from 39.9% to 13.5% in B. ovata, and from 45.8% to 14.3—23.2% in M. leidyi. The relationship between respiration rate (R) and wet weight (W) of individuals during the starvation can be expressed by power function R = R1 Wk (r2=0.85—0.94; P>0.001) for both ctenophore species. On average, k values were 0.95 and 0.83 in B. ovata and in M. leidyi, respectively. By the end of the starvation, metabolic rate per unit wet weight decreased by 33% in B. ovata and 46% in M. leidyi. Organic matter utilization was almost totally explained by respiration of ctenophores in the experiments and exceeded metabolic requirements of studied species by 11% and 15%, correspondingly. As compared with Mnemiopsis, Beroe has better tolerance to starvation which explains to some extent the success of the species survival during prolonged periods of food shortage in the Black Sea conditions.

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The New Maximum Length of the Striped Sea Bream (Lithognathus mormyrus L., 1758) in the Black Sea Region

AQUATIC SCIENCES AND ENGINEERING ◽

10.18864/ase201808 ◽

2018 ◽

pp. 50-52 ◽

Cited By ~ 1

Author(s):

Mehmet Aydın

Keyword(s):

Black Sea ◽

Maximum Length ◽

Sea Bream ◽

The Black Sea ◽

Black Sea Region ◽

Lithognathus Mormyrus

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The role of the isolation of the marginal seas during the Pleistocene in the genetic structure of black sea bream Acanthopagrus schlegelii (Bleeker, 1854) in the coastal waters of Japan

PeerJ ◽

10.7717/peerj.11001 ◽

2021 ◽

Vol 9 ◽

pp. e11001

Author(s):

Yutaro Yamashita ◽

Gustavo Sanchez ◽

Kentaro Kawai ◽

Satoshi Tomano ◽

Hiroki Fujita ◽

...

Keyword(s):

Population Structure ◽

Pacific Ocean ◽

Black Sea ◽

Coastal Waters ◽

Sea Bream ◽

The Black Sea ◽

Northwestern Pacific ◽

Marginal Seas ◽

Coastal Marine ◽

Japanese Waters

The black sea bream Acanthopagrus schlegelii (Bleeker, 1854) is a commercially important species in Japanese waters. Assessing its population structure is essential to ensure its sustainability. In the Northwestern Pacific, historical glacial and interglacial periods during the Pleistocene have shaped the population structure of many coastal marine fishes. However, whether these events affected the population of black sea bream remains unknown. To test this hypothesis and to assess the population structure of black sea bream, we used 1,046 sequences of the mitochondrial control region from individuals collected throughout almost the entire Japanese coastal waters and combined them with 118 sequences from populations distributed in other marginal seas of the Northwestern Pacific Ocean. As in other coastal marine fish with similar distribution, we also found evidence that the glacial refugia on the marginal seas prompted the formation of three lineages in black sea bream. These lineages present signatures of population growth that coincided with the interglacial periods of the Pleistocene. While the origin of Lineages B and C remains unclear, the higher relative frequency of Lineage A in the southernmost location suggests its origin in the South China Sea. The non-significant pairwise ΦST and AMOVA of Japanese populations and the presence of these three lineages mixed in Japanese waters; strongly suggest that these lineages are homogenized in both the Sea of Japan and the Pacific Ocean. Our results indicate that the black sea bream should be managed as a single stock in Japan until the strength of connectivity in contemporary populations is further addressed using non-coding nuclear markers.

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