Checklist of ascidians (Chordata, Tunicata) from the southern Gulf of Mexico

New Botrylloides, Botryllus, and Symplegma (Ascidiacea: Styelidae) in Coral Reefs of the Southern Gulf of Mexico and Mexican Caribbean Sea

Compound styelid ascidians are distributed in all marine environments and usually exhibit high morphological plasticity and complexity. In particular, Botrylloides, Botryllus, and Symplegma species show high morphological variations leading to confusion in traditional taxonomy assignments and to ambiguity in species delineation. Fewer than 20 species in these genera are registered in the Atlantic region. Here we surveyed the coral reefs of the southern Gulf of Mexico and Mexican Caribbean Sea, barcoded a total of 110 samples collected in seven reefs in 24 sites using mitochondrial cytochrome c oxidase subunit I (or 1), as well as performed a detailed morphological study. Species delimitation analyses of barcoding sequencing revealed twelve botryllid species and three Symplegma species. Two of the botryllid species were identified as Botrylloides niger and Botryllus humilis; the latter is the first record for the Gulf of México. The remaining 10 botryllid species and the two Symplegma species are not currently described in the literature and have no close matches in GenBank. One of the Symplegma samples could not be identified as an existing species and current characters do not support the description of a new species. Here we describe twelve new species, seven in Botryllus: B. bonanzus sp. nov, B. camur sp. nov., B. hartensis sp. nov., B. lambertorum sp. nov., B. nortensis sp. nov., B. tunnelli sp. nov., and B. unamensis sp. nov., three in Botrylloides: B. alacranensis sp. nov., B. ampullarius sp. nov., B. catalitinae sp. nov., and two in Symplegma: S. papillata sp. nov., and S. sisalensis sp. nov. We also present a tabular identification key of Botryllus, Botrylloides and Symplegma Atlantic species.

Marine Natural Products from the Yucatan Peninsula

Mexico is one of the three areas of the world with the greatest terrestrial and cultural biological diversity. The diversity of Mexican medicinal flora has been studied for a long time and several bioactive compounds have been isolated. The investigation of marine resources, and particularly the potential of Mexican marine resources, has not been intensively investigated, even though the Yucatan Peninsula occupies 17.4% of the total of the Mexican coast, with great biological diversity in its coasts and the ocean. There are very few studies on the chemistry of natural products from marine organisms that were collected along the coasts of the Yucatan Peninsula and most of them are limited to the evaluation of the biological activity of their organic extracts. The investigations carried out on marine species from the Yucatan Peninsula resulted in the identification of a wide structural variety of natural products that include polyketides, terpenoids, nitrogen compounds, and biopolymers with cytotoxic, antibacterial, antifouling, and neurotoxic activities. This review describes the literature of bioprospecting and the exploration of the natural product diversity of marine organisms from the coasts of the Yucatan Peninsula up to mid-2019.