Clustering evaluation of water quality for various classes of in-flow rivers in connected brackish lakes.

Brackish waters and estuaries at the lower reaches of rivers accumulate organic matter and nutrients from various sources in the watershed. Sufficient light and shallow water depth stimulate phytoplankton growth, resulting in a more diversified ecosystem with higher trophic levels. For effective watershed management, it is crucial to characterize the water quality of all rivers, including small and medium-sized ones.

A novel symbiotic relationship between ascidians and a new tunic-boring polychaete (Annelida: Spionidae: Polydora).

Polydora tunicola Abe, Hoshino Yamada, sp. nov., a new spionid species currently considered an obligate symbiont of styelid ascidians, is described based on materials collected from Polycarpa cf.