Sea anemones

Seven sea anemone species from coral reefs in the southern Gulf of Mexico are taxonomically diagnosed
and images from living specimens including external and internal features, and cnidae are provided. Furthermore,
the known distribution ranges from another 10 species are extended. No species records of sea
anemones have been previously published in the primary scientific literature for coral reefs in the southern
Gulf of Mexico and thus, this study represents the first inventory for the local actiniarian fauna.

RESUMEN. Se presenta el primer inventario de corales, octocorales y anémonas para el arrecife Enmedio, eco-sistema que forma parte del Sistema Arrecifal Lobos-Tuxpan (SALT). La información fue recabada de abril 2014 a noviembre 2015, realizando muestreos aleatorios en cinco sitios de las zonas de sotavento, planicie y barlovento. Las zonas arrecifales se caracterizaron mediante el número de especies registradas; y con base en el índice de Jaccard se determinaron diferencias/semejanzas. Se registró un total de 46 especies, las cuales están representadas por dos clases, seis órdenes, 25 familias y 31 géneros. El Orden Scleractinia fue el más diverso en especies. Se amplía el ámbito de distribución de Palythoa grandis y Eunicea mammosa para el suroeste del Golfo de México. Se adicionan 10 especies de anémonas y cinco de corales escleractinios como nuevos registros para el SALT. Las zonas arrecifales son disímiles en composición de especies y definen una marcada zonación, siendo sotavento la más importante por concentrar mayor riqueza de especies, atributo que decrece hacia barlovento. El arrecife Enmedio se considera importante en riqueza de especies y amerita especial atención al presentar tres especies con estatus de protección especial (Acropora cervicornis, Acropora palmata y Plexaurella dichotoma) de acuerdo a la Norma Oficial Mexicana. ABSTRACT. The present work reports the first inventory of corals, sea anemones, zoanthids and octocorals of the Enmedio reef, ecosystem that is part of the Lobos-Tuxpan Reef System. The information was gathered during the April 2014-November 2015 period. Five sampling sites were established in the leeward, flatland and wind-ward area. At each site random surveys were carried out to record species. The reef areas were characterized by considering the number of species recorded and using the Jaccard index to determine differences/similarities. A total of 46 species were recorded, which are represented by two classes, six orders, 25 families and 31 genera. The order Scleractinia was the most diverse in species. There is an extension in the distribution range of Palythoa grandis and Eunicea mammosa for the southwest Gulf of México. Ten species of sea anemones and five species of scleractinian corals were added as new records to the Lobos-Tuxpan Reef System. The reef areas are dissimilar in species composition and define a marked zonation. The leeward zone had the most importance because it has the highest species richness, an attribute that decreases towards the windward zone. The Enmedio reef is considered important in species diversity and merits special attention because it includes three species with special protection status (Acropora cervicornis, Acropora palmata y Plexaurella dichotoma) according to Mexican laws.

Ten species of sea anemones (Anthozoa: Actiniaria) are documented in the Mexican Caribbean based on observations and
collections in 11 coral reef localities during 2006–2011; three of them are new records for Mexico. These species belong
to families Actiniidae, Aiptasiidae, Aliciidae, Boloceroididae, Phymanthidae, and Stichodactylidae. Although these do not
represent all species reported in the Mexican Caribbean, these are the most abundant and conspicuous. This work represents
the first inventory of sea anemones of the Mexican Caribbean.

Global changes in the Anthropocene are affecting marine ecosystems in many ways, including alterations in long-established inter-species relationships. The Banggai cardinalfish Pterapogon kauderni, a species of global conservation concern, is highly dependent on benthic organisms serving as microhabitat. The objective of this study was to evaluate the effects of global change, in particular rising sea temperature, on P. kauderni and three key associated microhabitats: hard corals (Scleractinia), sea urchins (Diadematidae), and sea anemones (Actinia). Data collected before, during, and after the 2016 global coral bleaching event from P. kauderni habitat in the Banggai Archipelago, including coral bleaching (by genus) and P. kauderni (by life stage) microhabitat association (species or genus, coral life-form), were complemented by a literature review. While coral bleaching and mortality was less severe than in many other regions, hard coral genera and life-forms preferred by P. kauderni were disproportionately affected, and P. kauderni hosting sea anemones also bleached. Coral, sea urchin and sea anemone reproduction, larval development, and recruitment may be negatively affected. Likely post-settlement effects on sea urchin and sea anemone growth and survival are unclear. Direct impacts on P. kauderni are likely, including metabolic rate change with consequences for growth and longevity. Indirect impacts (e.g. changes in plankton composition and abundance, increased storm frequency/severity) will affect P. kauderni and all its microhabitats. This evaluation for P. kauderni, its key microhabitat groups, and their association, points towards increased need for both conservation action and research to fill identified knowledge gaps.