Sphaerodoridae (Annelida) is a seeming uncommon and minimally diverse group of polychaetes in the northwestern Atlantic, with only seven species reported from the United States, and none from the eastern coast of Canada, before the present study. Review of the large Smithsonian collection (National Museum of Natural History, Washington) revealed the presence of two morphologically extraordinary...

The intertidal and nearshore Nereididae of the Falkland Islands are detailed and a new species of Gymnonereis described. The new species, Gymnonereis tenera sp. n., is the first record of the genus for the Falkland Islands. It is, so far, only known from a few intertidal locations in fine and muddy sands. Main distinguishing characters are: jaw teeth absent (in adults), 3 papillae in Area V-VI,...

The presence of two species within the Eurythoe complanata complex in the Mediterranean Sea is reported, as well as their geographical distributions. One species, Eurythoe laevisetis, occurs in the eastern and central Mediterranean, likely constituting the first historical introduction to the Mediterranean Sea and the other, Eurythoe complanata, in both eastern and Levantine basins. Brief notes...

This paper describes a dataset of polychaetes (Annelida) from 14 midlittoral rocky shore sampling sites in Greece and Italy (Mediterranean Sea). The dataset combines the outcome of four different projects studying the hard substrate midlittoral zone in the Mediterranean between 1984 and 2009. Samples were collected by scraping and collecting the organisms from a framed area. The maximal samplin...

Many animals permanently inhabit the marine interstitium, the space between sand grains [1, 2]. Different evolutionary scenarios may explain the existence of interstitial animals [3, 4]. These scenarios include (1) that the interstitial realm is the ancestral habitat of bilaterians [5, 6], (2) that interstitial taxa evolved from larger ancestors by miniaturization, or (3) progenesis [3]. The fi...

A broad variety of body plans and subplans appear during a period of perhaps 8 million years (my) within the Early Cambrian, an unequaled explosion of morphological novelty, the ancestral lineages represented chiefly or entirely by trace fossils. Evidence from the fossil record can be combined with that from molecular phylogenetic trees to suggest that the last common ancestor of (i) protostome...

Brazilian specimens of Branchiosyllis cf. exilis, B. tamandarensis sp. n., Haplosyllis lattigae sp. n., H. loboi, Opisthosyllis brunnea and O. viridis are described and illustrated herein, from recently collected material; also, the distributions of Haplosyllis amphimedonicola and H. rosenalessoae are expanded to other localities in the states of Paraíba and Pernambuco. Branchiosyllis tamandare...

Jacques Loeb [5] showed that scientists could achieve artificial parthenogenesis [6] with one species of annelid [7] worm through a series of experiments in 1900. Loeb published the results of his experiments in 1901 as ?Experiments on Artificial Parthenogenesis [8] in Annelids (Chaetopterus) and the Nature of the Process of Fertilization,? in The American Journal of Physiology. His results bro...

This study recognises five species of Onuphis and four species of Aponuphis from southwestern Europe, represented in the Bay of Biscay, the Atlantic coasts of Iberia and the western Mediterranean Sea. One species, Onuphis anadonae sp. nov., is newly described and another species, Aponuphis willsiei Cantone & Bellan, 1996 is a new record for the Iberian Peninsula waters. Aponuphis ornata (Fauvel...