LAURENCIA MARILZAE (CERAMIALES, RHODOPHYTA) FROM THE MEXICAN CARIBBEAN: A NEW RECORD FOR THE TROPICAL WESTERN ATLANTIC

Laurencia marilzae Gil-Rodriguez, Senties & MT Fujii is recorded for the first time for the tropical western Atlantic Ocean, occurring in Isla Mujeres, Quintana Roo, Mexican Caribbean. The specimens were collected in November 2008 and June 2009, growing epilithically in the lower intertidal zone on moderately exposed rocky shores. This species is characterized by its distinctive yellow-orange color in the natural environment, four pericentral cells per vegetative axial segment, the presence of secondary pit-connections between adjacent cortical cells, which are markedly projecting at the apices, and by the presence of one ""corp en cerise"" per cell in all cells of the thallus: cortical, medullary, including pericentral and axial cells, and trichoblasts. Morphological similarities and molecular data support the determination of this material as L. marilzae. The present study expands the geographical distribution of L. marilzae to the Caribbean Sea in the tropical Western Atlantic Ocean.

Palisada flagellifera (Ceramiales, Rhodophyta) from the Canary Islands, Spain: a new record for the eastern Atlantic Ocean based on morphological and molecular evidence

Palisada flagellifera (Ceramiales, Rhodophyta) is recorded for the first time in the eastern Atlantic Ocean off Tenerife, La Gomera, La Palma and Fuerteventura, Canary Islands, Spain. The specimens were collected in 2006-2009 growing from the lower intertidal to subtidal zones to 2 m depth at sites exposed to wave action. The species possesses a palisade-like arrangement of cortical cells in cross section, lacks secondary pit connections between them, and has tetrasporangia produced by three fertile pericentral cells (the third and the fourth additional and the second that becomes fertile), and a right-angled arrangement of tetrasporangia. Gametangia were not observed. The phylogenetic relationships were inferred by analyses of the chloroplast-encoded rbcL gene sequences from 46 taxa. The Canarian and Brazilian P. flagellifera specimens formed a highly supported clade with a low level of genetic variation in the rbcL sequences (0.02-0.04%), confirming that they are the same taxonomic entity. This study expands the geographical distribution of P. flagellifera to the eastern Atlantic Ocean.

A new genus and new species of fan worms (Polychaeta: Sabellidae) from Atlantic and Pacific Oceans-the formal treatment of taxon names as explanatory hypotheses

Members of Parasabella minuta Treadwell, 1941, subsequently moved to Perkinsiana, were collected during a survey of rocky intertidal polychaetes along the state of Sao Paulo, Brazil. Additional specimens, which are referred to two new species, were also found in similar habitats from the Bocas del Toro Archipelago, Caribbean Panama, and Oahu Island, Hawaii. A phylogenetic analysis of Sabellinae, including members of P. minuta and the two new species, provided justification for establishing a new generic hypothesis, Sabellomma gen. nov., for these individuals. Formal definitions are also provided for Sabellomma minuta gen. nov., comb. nov., S. collinae gen. nov., spec. nov., and S. harrisae gen. nov., spec. nov., along with descriptions of individuals to which these hypotheses apply. The generic name Aracia nom. nov., is provided to replace Kirkia Nogueira, Lopez and Rossi, 2004, pre-occupied by a mollusk.

A new species of Trypanosyllis (Polychaeta : Syllidae) from Brazil, with a redescription of Brazilian material of Trypanosyllis zebra

A new species of Trypanosyllis was found in a collection of polychaetes living on algae, sponges, ascidians and sabelariid reef; at the intertidal zone of a rocky shore, at Praia do Guarau, south-eastern Brazil. Trypanosyllis aurantiacus sp. nov., is characterized by having an orange body in life, with dark red antennae and cirri throughout, falcigers with short, sub-bidentate blades, and parapodia with thick, distally sharp, protruding aciculae, two to three aciculae on each anterior parapodium, two aciculae on midbody segments, single acicula per parapodium on posteriormost chaetigers. Trypanosyllis aurantiacus sp. nov., is compared with the most similar congeners and a redescription of Trypanosyllis zebra, based on Brazilian specimens collected from similar environments at nearby beaches, is given.