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Scutellastra mexicana is the largest known patellid limpet species and probably is one of the most endangered marine invertebrates.The species was once distributed along the American Pacific coast from Mexico to Peru, but their large size (up to 35 cm long) and easy accessibility (shallow sublittoral), made it very vulnerable to human collection and now is extinct on most of the mainland Mexican coast.In August 2017, a large population of this species was found on María Cleofas island, off the coast of west‐central Mexico (Marías Archipelago, Pacific Ocean). This constitutes the only report of a population of this species since 1988.A total of 808 adult individuals of up to 26 cm in length and 20 cm in width were estimated, together with the presence of juveniles, suggesting that it is a self‐sustaining population. The population was monitored in August 2017 and August 2018.Although the species is under the category 'Special Protection' in the General Mexican Wild Law, and that María Cleofas island is a Biosphere Reserve, fishermen that operate with impunity in the area decimated the limpet population within a year of its discovery. Abundance in the shallowest area decreased significantly from 120 individuals per transect (65 m long and 2.75 m wide) in August 2017 to 48 individuals in August 2018, and the estimated adult population decreased from 808 to 304 limpets.Neither passive national conservation policies nor local practices have reduced current threats to biodiversity and resource depletion in Marías Archipelago. Protected areas like this are 'paper parks'—parks in name only—because there is no active conservation strategy or protection of marine species. [ABSTRACT FROM AUTHOR]

Racekiela montemfluminasp. nov. is the first species of the genusRacekielafound in freshwater habitats from Mexico. The species is abundant in small creeks at the northern side of State of Durango, located between 2500 and 2700 m altitude. The new species description is provided together within situphotographs of specimens, and SEM photographs of the spicules and gemmular structure. Two distinct classes of gemmuloscleres differing in size and shape (birotules and pseudobirotules) are present. The rotule of the birotula is discoidal, flat or slightly umbonate, with serrated margins and small crenulate teeth, or spines. The proportion of the diameter of the rotule vs. length of the shaft is the lowest of all theRacekielaspecies. Rotule of pseudobirotule is small, umbonate or with a prominent spike, and with hooks curved toward the shaft or almost straight. The birotules are embedded in the theca, but pseudobirotules protrude from the outer gemmular membrane. Fragments of cytochrome oxidase subunit I (COI) mtDNA, and internal transcribed spacers 1 and 2 (ITS1-5.8S-ITS2) rDNA were sequenced in order to establish the molecular identity and systematic position of genusRacekielaand the new species. COI showed an identical nucleotide composition with at least 11 spongillid-specimens from six previously sequenced species (GenBank). Phylogenetic analysis using the ribosomal region was concordant with previous information, which showed the monophyly of family Lubomirskiidae, and the non-monophyly of the families Spongillidae and Malawispongiidae. Specifically,Racekiela montemfluminasp. nov. erected as a sister clade of several species from the generaEphydatiaandCortispongilla.Our species constitutes the first representative of genusRacekielasequenced. This is also the first record of a freshwater sponge in Mexico in decades. www.zoobank.org/urn:lsid:zoobank.org:pub:71E826B6-59DC-475B-9391-27A7DED66E7A [ABSTRACT FROM PUBLISHER]