A Flatworm from the GenusWaminoa(Acoela: Convolutidae) Associated with Bleached Corals in Western Australia

Abstract

A flatworm isolated from bleached colonies of the coral Coscinaraea marshae at Rottnest Island, Western Australia, is described using a combination of morphological and molecular systematics. This flatworm shares morphological features characteristic of the genus Waminoa (Acoelomorpha: Acoela), including the presence of two algal symbionts, but appears to have genital regions different from those of other described species of Waminoa. The design of new oligonucleotide primers enabled the amplification of partial 18S rDNA of the Rottnest Island acoel specimens, and phylogenetic analysis positioned them within Waminoa, confirming their placement in the genus. Furthermore, Waminoa specimens from Rottnest Island grouped into a sister clade to Waminoa brickneri, indicating that the morphological and genetic differences observed are most likely intraspecific and due to geographic variation. As such, we name these Rottnest Island specimens W. cf. brickneri, but highlight that key differences warrant further exploration before assignment to this species can be confirmed. This is the first acoel flatworm described from Western Australia and contributes to our understanding of the diversity and evolutionary relationship of the Acoela.

Parasites and coral‐associated invertebrates that impact coral health

“…2005), Coral Sea (Winsor 1990), Indonesia (Haapkyla et al 2009), Micronesia (Trench & Winsor 1987), Western Australia (Cooper et al . 2015) and on the GBR (Winsor 1990). Waminoa spp.…”

Morphological and phylogenetic diversity of Waminoa and similar flatworms (Acoelomorpha) in the western Pacific Ocean

“…Polymerase chain reactions (PCR) were performed utilizing a HotStarTaq Plus Master Mix kit (Qiagen, Tokyo, Japan). A region of nuclear 18S ribosomal DNA was amplified using four primers; F1W Waminoa (5' -GCG CGG AGA GGT AGT GAC TAG T -3'), R1W Waminoa (5' -GTA GGT CGT CTT GCT GGG ATC -3'), F2W Waminoa (5' -CGT ATG CTT TAG TTG CTG CGT -3') and R2W Waminoa (5' -CGA TTT TGC AAC CCA TAC TCC -3') (Cooper et al 2015). These primers were used in three combinations, F1W Waminoa and R1W Waminoa, F2W Waminoa and R2W Waminoa, and F2W Waminoa and R1W Waminoa.…”

“…In order to compare with other Waminoa spp., additional previously reported GenBank sequences were included in the 18S rDNA alignment. The resulting 18S rDNA alignment contained 225 sequences of 417 -439 bp, including 22 sequences obtained from GenBank with a sequence of Eumecynostomum (AY297955) as outgroup in as a previous study (Cooper et al 2015). The CO1 alignment contained 96 sequences of 498 bp, with an outgroup sequence from GenBank (Amphiscolops bermudensis; FR837839).…”

“…From field observations, Waminoa spp. have been reported from Israel (Red Sea), Australia, Indonesia, Malaysia, Papua New Guinea, the Philippines, and Japan (Pacific Ocean) (Winsor, 1990;Gosliner et al, 1996;Ogunlana et al, 2005;Barneah et al, 2007a;Haapkylä et al, 2009;Humann and DeLoach, 2010;Matsushima et al, 2010;Barneah et al, 2012;Hoeksema et al, 2011;Hoeksema and Farenzena, 2012;Cooper et al, 2015;Kunihiro and Reimer, 2018;Biondi et al, 2019), and the genus is thought to be widely distributed in subtropical to tropical regions of the Indo-Pacific Ocean. No records are known from the Atlantic.…”

“…Waminoa spp. are found on host anthozoans and until now have been reported from at least 32 genera of scleractinian corals (Winsor, 1990;Ogunlana et al, 2005;Barneah et al, 2007a;Haapkylä et al, 2009;Matsushima et al, 2010;Hoeksema et al, 2011;Barneah et al, 2012;Hikosaka et al, 2012;Hoeksema and Farenzena, 2012;Wijgerde et al, 2012;Cooper et al, 2015;Kunihiro and Reimer, 2018;Biondi et al, 2019), three genera of alcyonacean octocorals (Winsor, 1990;Ogunlana et al, 2005;Barneah et al, 2007a;Haapkylä et al, 2009;Kunihiro and Reimer, 2018) and one genus of zoantharians (Kunihiro and Reimer, 2018;Biondi et al 2019). In south-east Sulawesi, Indonesia, a quantitative survey of Waminoa was conducted, showing Waminoa to be associated with at least 16 taxa of scleractinians or alcyonaceans (Haapkylä et al, 2009).…”