Mitochondrial and nuclear gene sequencing confirms the presence of the invasive sea anemone Diadumene lineata (Verrill, 1869) (Cnidaria: Actiniaria) in Argentina

GONZÁLEZ MUÑOZ, RICARDO; LAURETTA, DANIEL; BAZTERRICA, MARÍA CIELO; PUENTE TAPIA, FRANCISCO ALEJANDRO; GARESE, AGUSTÍN; BIGATTI, GREGORIO; PENCHASZADEH, PABLO E.; LOMOVASKY, BETINA; ACUÑA, FABIÁN H.

PeerJ

PeerJ

Lugar: California; Año: 2023 vol. 11 p. 1 - 18

Background: Diadumene lineata is one of the most widespread sea anemone speciesworldwide. Although this species has been reported a few times on the Argentinecoast since 2004, its identification has traditionally been based on externalmorphological characteristics, and in most cases no voucher specimens are availableto support previous records.Methods: In this study, we obtained DNA sequences of two mitochondrial markers(12S and 16S) and two nuclear markers (18S and 28S) from specimens of D. lineatacollected in two locations on the Argentine coast separated by almost 800 km.Additionally, we conducted an analysis of the morphology, as well as the types andsize ranges of cnidae, using specimens collected at three different locations along theArgentine coast. Furthermore, since introduced populations of D. lineata arepresumably ephemeral and only reproduce asexually outside their native range, weexamined the internal anatomy of representatives from the Argentine coast forgametogenic tissue as an indication of whether they might be capable of sexualreproduction.Results: DNA data support our morphological identification, including cnidaeanalyses, of the specimens as D. lineata. Furthermore, all specimens examined weredetermined to be sterile.Discussion: Genetic sequence comparisons, phylogenetic reconstruction, and cnidaedata support the identification of individuals of D. lineata from Mar Chiquita andGaripe Beach, confirming the presence of the species on the Argentine coast usingboth morphological and molecular tools. The absence of fertile specimens suggeststhat each sampled population is likely reproducing only by asexual reproduction andpossibly composed of clones. The presence of an additional category of longer pmastigophores B2a in the actinopharynx and filaments, as well as holotrichs in thecolumn, is also reported.Conclusions: For the first time, we have confirmed the presence of D. lineata inArgentina through molecular data. Additionally, our findings indicate that theanalyzed specimens are sterile, suggesting that this species is not engaging in sexualreproduction in the studied localities. It is crucial to continue monitoring thepopulations of D. lineata along the Argentine coast to assess whether they establishsexual reproduction, expand their distribution range or disappear, or potentiallycause any harm to local species or alterations in benthic communities.