Sauvage T., Payri C., Draisma S.G.A., Prud′homme van Reine W.F., Verbruggen H., Belton G.S., Gurgel C.F.D., Gabriel D., Sherwood A.R. and Fredericq S. 2013. Molecular diversity of the Caulerpa race...

Copyright © 2011 International Phycological Society.Comparative rbcL sequence analysis indicates that the species going under the name Schizymenia dubyi in the Azores should be referred to as S. apoda. Sequences of Schizymenia specimens from China and Namibia were also identified as S. apoda, of which the type locality is the Cape Province in South Africa. Schizymenia dubyi, described from Atlantic France, is clearly a distinct species that we here report for Japan and Sicily in the Mediterranean Sea. Both Schizymenia species, along with an unreported species from Japan, are distinct from S. pacifica described from Washington, in the Pacific Coast of North America. Secondary pit connections were observed in gametophytes of S. apoda from the Azores, a previously unknown character for the Nemastomatales. Examination of type material of Nemastoma confusum indicates that this species, currently placed in the Nemastomataceae, should be transferred to the genus Platoma in the Schizymeniaceae. A morphological comparison between Platoma confusum (Kraft & John) comb. nov. with descriptions of P. cyclocolpum and P. chrysymenioides suggests that the three species are closely related

Large masses of pelagic Sargassum occur in the Atlantic Ocean between the latitudes 5°S and 38°N. Since 2011, inundations have happened in the Gulf of Mexico, the Caribbean, and West Africa, affecting biological communities and economies. A series of severe weather events in the Azores led to a Sargassum inundation between mid-December 2023 and early April 2024, here reported for the first time. Although the sea reclaimed most of the stranded algae, 555 metric tons were removed. Periodic inundations may represent an introduction pathway for non-native species since massive amounts of organisms are deposited alive on the coast. Besides the ecological impact, the inundations can be harmful to human health and impact the tourism sector. Further studies on the expected changes in the frequency and severity of storms in the region are necessary to evaluate the probability of new inundations. Measures to attenuate possible impacts should also be searched.

Genera in the Rhodymeniaceae Harvey that have a hollow thallus lacking diaphragms have been placed in Chrysymenia J. Agardh 1842 (including Gloiosaccion Harvey 1859), Botryocladia (J. Agardh) Kylin 1931, Irvinea Guiry in Saunders et al. 1999, and Cresia C. Lozada-Troche, D.L. Ballantine & H. Ruíz 2010. Chrysymenia has traditionally been defined by a lack of internal rhizoids and with the only solid portion of the thallus limited to the stipe. Botryocladia has been differentiated from Chrysymenia by the presence of larger, solid axes. Our results suggest that on the basis of vegetative characters alone, the true Chrysymenia clade contains specimens that exclusively produce gland cells directly on unmodified medullary cells, whereas Botryocladia and Cresia may or may not cut off gland cells from modified gland-supporting medullary cells. On the basis of comparative rbcL and SSU sequence analyses and morphological data, the hollow, gelatinous species Chrysymenia enteromorpha Harvey from the Gulf of Mexico and Caribbean Sea, and Chrysymenia wrightii Harvey described from the northwest Pacific Ocean are newly transferred to the genus Botryocladia as Botryocladia enteromorpha (Harvey) comb. nov. and B. wrightii (Harvey) comb. nov., respectively.