Fig 1.
A) Terminology used in this paper p: Proloculus; f: Flexostyle; d: Deuteroconch; B) Explanation of the biometric methods used in the paper. α is the angle between the lines connecting the proximal intersect of the deuteroconch with the flexostyl (a), the center of the protoconch (c) and the lateral intersect of the deuteroconch with the flexostyle (b). The diameter of the embryonic apparatus is the maximum diameter of the protoconch+ deuteroconch+flexostyle (d). C) Terminology used in the axial section: l: Lateral chamberlets; m: Median skeleton or marginoporid structure (stolons of this structure form the median apartures on the apertural face); ac: The plane formed by the annular stolons of each chamberlet. These end in the median apertures on the apetural face. Scale bar = 100 μm.
Fig 2.
A) Variation in α (angle between the lines connecting the proximal intersect of the deuteroconch with the flexostyl) between the four Amphisorus morphotypes. Numbers indicate the number of analysed specimens B) Frequency diagram of the diameter of the embryonic apparatus (d in Fig 1) in Spermonde (A) and West Australia (B). Colors correspond to the morphotypes.
Fig 3.
Virtual vertical cross sections through the A forms of the four morphotypes of Amphisorus recognised in this paper.
A) Spermonde Large (SpL). Note the intermediate skeleton rapidly increasing in thickness towards the margin, while the marginal chamberlets are well developed and have a more or less constant thickness following the development of the intermediate skeleton. B) Spermonde Small (SpS). Note the absence of the intermediate skeleton. C) West Australia Large (WAL). Note the intermediate skeleton increasing in thickness towards the margin, while the marginal chamberlets are narroe and become thinner towards the margin. D) West Australia small (WAS). Note the absence of the intermediate skeleton. Scale bar = 200 μm.
Table 1.
Comparison of morphological characters of Amphisorus morphotypes described in this study (West Australia Large (WAL), West Australia Small (WAS), Spermonde Large (SpL), Spermonde Small (SpS)) and previously described Amphisorus species.
Fig 4.
Map showing the sampling locations in Australia and Indonesia, and median-joining networks showing the four Amphisorus genotypes (based on a 4,307bp fragment spanning the partial 18S rRNA, 5.8S rRNA, and partial 28S rRNA), and three Fugacium Fr5 genotypes (based on a 606bp 28S rRNA fragment).
Each circle in the network represents a distinct genotype. Colours indicate the morphotype of analysed Amphisorus specimens. Each black bar indicates one substitution. Circle size corresponds to the number of specimens.
Fig 5.
NMDS plots showing the community composition of 26 Amphisorus-associated bacteria based on Bray-Curtis distance.
A) Differences in bacterial community composition between WAS and WAL morphotype. B) Differences in bacterial community composition between sampling sites.