A new record of Avrainvillea cf. erecta (Berkeley) A. Gepp & E. S. Gepp (Bryopsidales, Chlorophyta) from urbanized estuaries in the Hawaiian Islands

Abstract

BackgroundA second species in the siphonous green algal genus Avrainvillea was recently discovered off the island of O‘ahu in the Main Hawaiian Islands. Specimens were collected from Honolulu Harbor, including its entrance channel, and near Ke‘ehi Harbor. These locations are both in Mālama Bay on O‘ahu’s south shore in or adjacent to urbanized estuaries, respectively. In situ observations, morphological and molecular assessments were conducted to examine the alga’s habit and distribution, as well as to assess its putative species identification.New informationThe alga occurred in sand as single individuals or in clusters of several individuals at both sites, and near or within seagrass beds (Halophila decipiens) and algal meadows composed of the green alga Halimeda kanaloana and an unidentified Udotea species at the Ke‘ehi Harbor site. All analyses supported both populations as representative of the same taxa, reported until further investigation in the broad Pacific as Avrainvillea cf. erecta based on morphological and molecular analyses. This record of a second Avrainvillea species in Hawai'i is of particular concern considering that an alga recognized as A. amadelpha, first observed in 1981 from two locales on O‘ahu’s south shore, has become invasive in Hawai‘i’s intertidal to mesophotic environments.

Diversity of Kallymeniaceae (Gigartinales, Rhodophyta) associated with Hawaiian mesophotic reefs

“…In summary, this study represents a step towards increasing our understanding of mesophotic diversity and taxonomy, tripling the number of known genera in the family Kallymeniaceae in Hawai`i (Abbott, 1999), and joining a growing body of work characterizing the algal diversity of Hawaiian MCEs Spalding, 2012; Silva & Chacana, 2014;Spalding et al, 2016;Wade et al, 2018;Sauvage et al, 2019;. Additionally, the present study underscores how much undescribed biodiversity remains in the archipelago, and that even dwarf stipitate red blades deserve systematic attention for detection of biodiversity.…”

The Ulvophyceae (Chlorophyta) of eastern Sorsogon, Philippines, including Halimeda magnicuneata sp. nov. (Bryopsidales)

“…Its occurrence in the Philippines is therefore not unexpected. Although identifying A. amadelpha can be difficult (Wade et al 2018), it can however be distinguished from the morphologically similar species A. lacerata J.Agardh. In the latter species, the stipes are more distinct and the blades composed of tightly woven filaments resulting in a papery texture (Coppejans et al 2017).…”

Taxonomic determination of the cryptogenic red alga, Chondria tumulosa sp. nov., (Rhodomelaceae, Rhodophyta) from Papahānaumokuākea Marine National Monument, Hawai‘i, USA: A new species displaying invasive characteristics

“…A . lacerata has now spread into shallow waters in recent decades from deeper habitats [ 2 , 5 , 6 , 7 ]. More recently, Avrainvillea erecta (Berkeley) A.Gepp & E.S.Gepp has been recorded on O‘ahu and Maui as an introduced species, and continues to rapidly increase in abundance and distribution [ 6 ].…”

“…lacerata has now spread into shallow waters in recent decades from deeper habitats [ 2 , 5 , 6 , 7 ]. More recently, Avrainvillea erecta (Berkeley) A.Gepp & E.S.Gepp has been recorded on O‘ahu and Maui as an introduced species, and continues to rapidly increase in abundance and distribution [ 6 ]. In contrast to the Main Hawaiian Islands, reports of nuisance algae in Papahānaumokuākea Marine National Monument (PMNM) (the Northwestern Hawaiian Islands) are far fewer, and no invasive behavior by non-indigenous seaweeds has been observed.…”