Ecohydraulogical Characteristic Index System of Schizopygopsis younghusbandi during Spawning Periods in the Yarlung Tsangpo River

To address the species decline in aboriginal fish in the Yarlung Tsangpo River Basin and the lack of research on the habitat characteristics of fish spawning grounds, this paper studied the changing trends in runoff in spawning grounds and the habitat conditions characteristics of Schizopygopsis younghusbandi during the spawning period. In conventional approaches, inaccurate statistical results are obtained when a full river section is taken as the region to be assessed, so a new method for determining the statistical boundaries of characteristic indexes was proposed. By combining hydrological analyses, mathematical statistics, and numerical simulations, the statistical boundary of the index was determined, and a suitable range for the habitat characteristic indexes for the spawning field was finally obtained. The results showed that (1) the maximum percentage of the statistical boundary for the spawning grounds was 39% near the banks on both sides of the river; (2) the flow during the spawning period exhibited small variations, a short duration and a fluctuation cycle and was dominated by water rising events, and the interannual growth trend in the daily flow was obvious; and (3) during the spawning period, the flow velocity of the fish habitat was small, the turbulence level of the fluid was low, and the flow regime was stable. A suitable range for the habitat characteristic index of the target fish provided the basic data for the protection of aboriginal fish and was beneficial to maintain the balance of aquatic ecological system in the Yarlung Tsangpo River. The results of this study contribute to the rational development of water resources in the basin and the protection of species diversity and water environment.

Addition to the lichen flora of Russia. III. Thelopsis isiaca (Stictidaceae) and notes on Thelopsis in the Caucasus

Suboceanic species Thelopsis isiaca Stizenb. and T. rubella Nyl. are reported for the first time for Russia from the Caucasian Black Sea Coast (Krasnodar Territory). Detailed description, habitat characteristic, ecology and general distribution of Mediterranean-Atlantic species T. isiaca are presented. This species grows on the trunk of Juniperus excelsa in the sub-Mediterranean xerothermic undisturbed pistacia-juniper habitats on the Abrau peninsula, Nature Reserve «Utrish». Notes on the Caucasian species of Thelopsis Nyl. (T. flaveola Arnold, T. isiaca, T. melathelia Nyl., T. rubella) are given, and a key to the species is provided.

New Records of Seagrass Flora in Air Bangis West Sumatera

Seagrasses in the Air Bangis Archipelago, west coast of Sumatra were found growing in sandy muddy substratesof the shallow coastal waters at depth of 0.3-2.5 m, dominated by degraded coral reefs around the off-shoreislands. Two species; Enhalus acoroides (L.f) Royle and Thalassia hemprichii (Ehrenb) Aschers were observed atPulau Unggas, Pulau Pasir Panjang and Teluk Tapang. Halodule uninervis (Forssk) Aschers was observed in twolocations; Pasir Panjang and Teluk Tapang. The occurrence of this species is unknown previously and therefore itis a new flora record for Sumatra. With this new record, Sumatra has six species of seagrasses, contributing tohalf of total number of seagrasses occurring in Indonesia. According to leaf width measurements, two morphologicalvariants (narrow and wide leaved) can be distinguished for Halodule uninervis. In addition, descriptions of thespecies and their habitat characteristic are provided.