A New Species of Natsushima Living in the Deep-sea Solemyid Clam

Natsushima (Annelida: Chrysopetalidae) is a genus of obligate symbionts that inhabit the mantle cavity of deep-sea chemosynthetic bivalves, yet it remains poorly understood, with three species described. We describe a new species of Natsushima hosted by a deep-sea solemyid clam (Acharax haimaensis) from the Haima cold seep in the South China Sea, using an integrative morphological and molecular approach, expanding the known diversity of Natsushima from three to four. A comprehensive key for identifying these species is provided. Our study supports the hypothesis that Natsushima co-evolved and co-speciated with their hosts. Acharax is globally distributed in the deep-sea vent and seep ecosystems. Thus, examining hosts from diverse regions may reveal more Natsushima species and offer further insights into the biogeographical pattern and divergence histories of these holobionts.

Figure Legend: Natsushima nanhaiensis n. sp. A, Specimens in their habitat; B, whole specimen, dorsal view; C, anterior end, dorsal view; D, posterior end, ventral view; E, ventral chaetae. Scale bars: A = 20,000 µm, B-D = 1000 μm; E = 3 μm.

Read the full article, published by Zoological Studies, here

Follow Zoological Studies on Twitter @ZooStudies and Facebook