Novel phenotypes are often linked to major ecological transitions during evolution. Here, we describe for the first time an unusual network of large blood vessels in the head of the sea snake Hydrophis cyanocinctus . MicroCT imaging and histology reveal an intricate modified cephalic vascular network (MCVN) that underlies a broad area of skin between the snout and the roof of the head. It is mostly composed of large veins and sinuses and converges posterodorsally into a large vein (sometimes paired) that penetrates the skull through the parietal bone. Endocranially, this blood vessel leads into the dorsal cerebral sinus, and from there, a pair of large veins depart ventrally to enter the brain. We compare the condition observed in H. cyanocinctus with that of other elapids and discuss the possible functions of this unusual vascular network. Sea snakes have low oxygen partial pressure in their arterial blood that facilitates cutaneous respiration, potentially limiting the availability of oxygen to the brain. We conclude that this novel vascular structure draining directly to the brain is a further elaboration of the sea snakes' cutaneous respiratory anatomy, the most likely function of which is to provide the brain with an additional supply of oxygen.

Acclimation culture and trial culture of two sea snake species Hydrophis curtus and H. cyanocinctus in composite tanks were conducted to determine growth, survival rate, predation behavior and prey selection. The results showed that adults of H. curtus and H. cyanocinctus did not capture any prey such as anchovy, eel and shrimp in a period of 30 days of acclimation culture. The body weight of two these species reduced gradually from 783.3 ± 76.4 g and 360.0 ± 60.0 g to 660.0 ± 135.2 g and 315.0 ± 77.8 g, respectively. Survival rate was 100% in H. curtus and 80% in H. cyanocinctus. Meanwhile, the results of acclimation culture of sea snake juvenile revealed that frozen anchovy was preferred prey in both of two species. The body weight of H. curtus increased from 49.8 ± 0.5 g to 70.0 ± 8.2 g and that of H. cyanocinctus was 44.3 ± 3.1 g to 47.1 ± 5.2 g. The prey capture rate of H. curtus and H. cyanocinctus was 100% and 60%, respectively. Survival rate of the juvenile of two species was 100% after 30 days of acclimation culture. In 60 days of trial culture, similar results as acclimation culture were observed in adults of two sea snake species, they still did not capture any prey and the body weight reduced gradually. The result of 60-day culture of sea snake juvenile showed that the prey capture rate was 100% in both of two species. The body weight of H. curtus and H. cyanocinctus increased from 70.0 ± 8.2 g and 57.5 ± 5.8 g to 78.3 ± 15.3 g and 65.0 ± 14.1, respectively. SGR of H. curtus was 0.16 ± 0.32 %/day and that of H. cyanocinctus was 0.52 ± 0.36%/day. The survival rate of H. curtus and H. cyanocinctus was 60% and 40% in period of 60 day trial.

Temperature and wind on the sea surface are factors affecting the development of coral reefs in the seawaters. The research results show that the warming of sea water under the condition of weak wind field is considered a major threat to the bleaching of coral reefs in the sea areas of the Ninh Thuan - Binh Thuan provinces.

The study was carried out during the period from June, 2003 to October, 2004 in the coastal waters of southern central Vietnam (from Da Nang city to Vung Tau city). There were 39 species of poisonous marine  products that can causes a number human deaths. They belonging to three Phyla: Mollusca: 3 species:  (Cephalopoda: I species: Greater blue-ringed octopus (Hapalochaena lunulata Q. & G., 1832); Gastropoda: 2 species: Geographus conus snail (Conus geograpus L., 1758) and Textile conus snail (onus textile L., 1758), Arthropoda: 4 species: (Crustacea: 3 species: Devil crabs (Zosimus aeneus L., 1958); Floridus crabs  (Atergastis floridus L., 1758); (Platrpodia granulosa Ruppell, 1830); Merostomata: 1 horseshoe crabs (Carcinoscorpius rotundicauda Latreille, 1826) and Vertebrata 32 species: Snapper: 1 species: Two-spot red  snapper (Lutjanus bohar Forskal, 1775); Goby: 1 species: Shadow goby (Yongeichthys ne bulosus Forskal, 1775), mainly 21 species puffer of family Tetraodontidae. The Reptilia are 9 species sea snake of subfamily Hydrophinae.