Eukaryotic Life Inhabits Rhodolith-forming Coralline Algae (Hapalidiales, Rhodophyta), Remarkable Marine Benthic Microhabitats

Abstract

Rhodoliths are benthic calcium carbonate nodules accreted by crustose coralline red algae which recently have been identified as useful indicators of biomineral changes resulting from global climate change and ocean acidification. This study highlights the discovery that the interior of rhodoliths are marine biodiversity hotspots that function as seedbanks and temporary reservoirs of previously unknown stages in the life history of ecologically important dinoflagellate and haptophyte microalgae. Whereas the studied rhodoliths originated from offshore deep bank pinnacles in the northwestern Gulf of Mexico, the present study opens the door to assess the universality of endolithic stages among bloom-forming microalgae spanning different phyla, some of public health concerns (Prorocentrum) in marine ecosystems worldwide.

Sporolithon sinusmexicanum sp. nov. (Sporolithales, Rhodophyta): a new rhodolith-forming species from deepwater rhodolith beds in the Gulf of Mexico

“…Comments: Unidentified spherical inclusions were observed in the perithallium of specimen LAF 6970B, which may be unidentified life history stages of microalgal organisms (Fig. 23), as reported in Krayesky-Self et al (2017). …”

“…Wegeberg and Pueschel (2002) documented that in other coralline algae, such as Lithothamnion Heydrich and Phymatolithon Foslie in the Hapalidiales, the sloughing off of epithallial cell layers can become replenished with a unique type of intercalary meristem. Since Krayesky-Self et al (2017) documented with SEM, TEM and fluorescence microscopy previously unrecognized benthic life history stages of bloom-forming microalgae such as dinoflagellates (i.e. Prorocentrum lima (Ehrenberg) F.Stein) and haptophytes (i.e.…”

First Report of Endolithic Members of Rhodosorus marinus (Stylonematales, Rhodophyta) Growing Inside Rhodoliths Offshore Louisiana, Northwestern Gulf of Mexico

“…Biogenic rhodoliths (Figure 1a) are formed by the non-geniculate CCA themselves, e.g., Lithothamnion sp. In contrast, autogenic rhodoliths are derived from already existing calcium carbonate rubble established by differential erosion processes of the caprock (Gore, 1992), with the rubble becoming secondarily covered by various encrusting and fleshy algae (Felder et al, 2014;Fredericq et al, 2014;Richards et al, 2016;Krayesky-Self et al, 2017;Schmidt et al, 2017). Autogenic rhodoliths are viewed as a specific type of nucleated rhodoliths (sensu Freiwald and Henrich, 1994) in which the core derives from calcium carbonate rubble as opposed to other materials.…”

“…Autogenic rhodoliths are viewed as a specific type of nucleated rhodoliths (sensu Freiwald and Henrich, 1994) in which the core derives from calcium carbonate rubble as opposed to other materials. These two categories of rhodoliths co-inhabit the same rhodolith beds but the internal (endolithic) microbiome of each category may differ with regard to the diversity of taxa (biogenic: Krayesky-Self et al, 2017, andautogenic: Sauvage et al, 2016a;Fredericq et al, 2019).…”

Perspectives on the Great Amazon Reef: Extension, Biodiversity, and Threats

“…Oil exploration within the GARS poses serious threats to the biodiversity and sustainability of the region and the minimal data attained so far indicate that precaution is needed before starting any activity with great potential for reef degradation. For example, an oil spill in the Gulf of Mexico caused by the explosion of the BP-operated Deepwater Horizon (DWH) offshore oil rig led to a large-scale environmental catastrophe, largely impacting reefs and rhodolith beds (Goodbody-Gringley Krayesky-Self et al, 2017). The use of oil dispersant to prevent floating oil from reaching the shore caused even more damage to reef communities in the Gulf of Mexico, as the widely used dispersant (Corexit R ) causes oil to sink, suffocating benthic communities, as well as decreased coral larvae settlement and survival (GoodbodyGringley et al, 2013).…”