Comparative Tissue Responses of Marine Mollusks on Seasonal Changes in the Northern Adriatic Sea

In the shallow Northern Adriatic, marine mollusks are affected by bottom trawling and seafood disturbance. Seasonal oscillations of oceanographic factors additionally influence their physiology, stress responses and survival. Tissue responses to seasonal variations in green ormer (Haliotis tuberculata L.) and Mediterranean scallop (Pecten jacobaeus L.) in the Northern Adriatic have not been reported. Hence, their biochemical and antioxidant defense properties over seasons were studied and the microanatomical structure of their tissue was correlated with function. Histological analysis of gonads revealed two peaks of gonadal maturation and spawning during the spring/summer period and winter season for scallops, and one peak during the fall for ormers. The gonadal maturation of both species was correlated with their seasonal variations of metabolic demands and antioxidant capacity. The lipid vacuoles of tubuloacinar terminations in the digestive gland differed between the two species; in scallop they are several-fold larger in size and number. Low temperatures in winter contributed to a decline in enzymatic antioxidant defense in scallop tissues, having lower superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, and higher concentrations of thiobarbituric acid reactive substances (TBARS) and total antioxidant status (TAS). In ormers, winter induced lower TAS, TBARS, SOD and GPx concentrations. The significant difference of winter TAS and TBARS levels between ormers and scallops was correlated with variations in their reproductive cycles, as well as in antioxidant defense systems. The most important factor for stress-related parameters for both species in this work was found to be the season-induced temperature change.

Gift to the Chief: A Roman Amphora with the Sestius Stamp from the Pushkin SMFA

The amphorae collection of the Pushkin State Museum of Fine Arts (SMFA) stores the rarest for the Black Sea region sample of Roman amphora of the first half of the 1st century BC with the Latin stamp SES “anchor”. Judging by the presence of traces of marine mollusks on the outer surface, the vessel comes from the sea. Under the act of transfer the amphora was received in the Pushkin State Museum of Fine Arts from the Kremlin Museums in 1965. The stamp makes it possible to confidently define the vessels origin from the workshops of the Roman colony Cosa (modern Tuscany territory), which belonged to the famous plebeian Sestius family, who Cicero corresponded with. Additionally, it has been suggested that the amphora may originate from the famous Grand Congloue shipwreck near Marseille, explored in the post-war period by J.I. Cousteau.

Cave Sites of the Jomon Period in Taishaku Gorge, Western Japan

We describe the largest group of cave sites in Japan known to date. It includes some 50 sites, located in a gorge within the area of the modern Taishaku National Natural Park. Their characteristics are provided and their relevance to the study of the early stages of the Jomon Period is assessed. The study is based on publications, fi eld reports, and samples of artifacts owned by the museums in the Hiroshima Prefecture. The focus is on cave sites in the Chugoku region, their location, structure, inner space, and utility zones in the adjoining territory. Special attention is paid to the reconstruction of sequence in which parts of the cave space were exploited at different stages of the Jomon Period. Archaeological fi nds are described in detail—stone and bone tools, potsherds, and mollusk shells. Their analysis suggests that the Jomon people who lived in those caves subsisted mostly by hunting and freshwater mollusk collecting. Shells of marine mollusks and tools made of sanukite, which is unavailable in the area, indicate trade relations between cave dwellers and people of the adjoining regions, including the sea coast. A conclusion is made that population growth and greater reliance on hunting and fi shing territories rich in vegetation led to the change in lifestyle and subsistence strategies of the Jomon people.

Biochemical Characterization of a Novel Endo-1,3-β-Glucanase from the Scallop Chlamys farreri

Endo-1,3-β-glucanases derived from marine mollusks have attracted much attention in recent years because of their unique transglycosylation activity. In this study, a novel endo-1,3-β-glucanase from the scallop Chlamys farreri, named Lcf, was biochemically characterized. Unlike in earlier studies on marine mollusk endo-1,3-β-glucanases, Lcf was expressed in vitro first. Enzymatic analysis demonstrated that Lcf preferred to hydrolyze laminarihexaose than to hydrolyze laminarin. Furthermore, Lcf was capable of catalyzing transglycosylation reactions with different kinds of glycosyl acceptors. More interestingly, the transglycosylation specificity of Lcf was different from that of other marine mollusk endo-1,3-β-glucanases, although they share a high sequence identity. This study enhanced our understanding of the diverse enzymatic specificities of marine mollusk endo-1,3-β-glucanases, which facilitated development of a unique endo-1,3-β-glucanase tool in the synthesis of novel glycosides.

Diversity of benthic marine mollusks of the Strait of Magellan, Chile (Polyplacophora, Gastropoda, Bivalvia): a historical review of natural history

An increase in richness of benthic marine mollusks towards high latitudes has been described on the Pacific coast of Chile in recent decades. This considerable increase in diversity occurs specifically at the beginning of the Magellanic Biogeographic Province. Within this province lies the Strait of Magellan, considered the most important channel because it connects the South Pacific and Atlantic Oceans. These characteristics make it an interesting area for marine research; thus, the Strait of Magellan has historically been the area with the greatest research effort within the province. However, despite efforts there is no comprehensive and updated list of the diversity of mollusks within the Strait of Magellan up to now. This study consisted of a complete bibliographic review of all available literature that included samples of mollusks in the Strait of Magellan. More than 300 articles were reviewed, covering 200 years of scientific knowledge. There were 2579 records belonging to 412 taxa, of which 347 are valid species. Of the total valid species, 44 (~13%) are considered of doubtful presence in the Strait. This work increases the known richness of mollusks of the Strait of Magellan by 228%; it is also the first report that integrates all available diversity studies of the three most speciose classes of benthic mollusks (Gastropoda, Bivalvia and Polyplacophora) from the Strait of Magellan.

Recent progress in marine mollusks from the South China Sea: chemical and ecological studies

: Marine mollusks are a prolific source of secondary metabolites with complex/diverse structures and various aspects of biological activities. For above mentioned reason, these animals have been being extensively explored and became the hotspot of research subject in the recent years. It is well documented that mollusks can escape from predation by utilizing bioactive metabolites as defensive chemicals. In the last decade, the possible diet relationship between the South China Sea mollusks and their related potential prey organisms, including sponges, corals, algae, etc. have been systematically investigated. A series of interesting results have been obtained concerning the chemistry, chemoecology and pharmacological profiles of the studied marine organisms. The present review focuses on recent development dealing with chemistry, chemoecology, and bioactivity of the South China Sea mollusks and their dietary organisms.