Re-evaluation of the morphology of the monotypic genera Lycastonereis Rao, 1981 and Ganganereis Misra, 1999 (Annelida, Phyllodocida, Nereididae).

The monotypic genera Lycastonereis Rao, 1981 and Ganganereis Misra, 1999, and their respective species L. indica Rao, 1981 and G. sootai Misra, 1999, have unique morphological traits, and are only known from India and nearby countries. Lycastonereis is diagnosed by having three pairs of anterior cirri and biramous parapodia, whereas for Ganganereis the pharynx has partially sclerotized papillae arranged in a semi-continuous row in the maxillary ring, and chaetae include only spinigers throughout the body. The morphology of these species is not adequately understood as shown by their exclusion in phylogenetic analyses, and therefore an additional morphological evaluation is needed. The re-evaluation of the genera is based upon three specimens of L. indica and the original description of G. sootai. It is shown that L. indica has rounded papillae present in both maxillary and oral rings (not restricted to the oral ring), and in all areas except area V, and neuroacicular ligules are bilobed (not the postchaetal lobes). In addition, G. sootai is morphological similar to species of Paraleonnates Khlebovich Wu, 1962, mainly in the arrangement and kind of structures of the pharynx, parapodial morphology, and chaetae; therefore, G. sootai is transferred to Paraleonnates, and Ganganereis is regarded as a junior synonym of Paraleonnates. A key to species of Paraleonnates is included.

New species of Pseudonereis Kinberg, 1865 (Polychaeta: Nereididae) from the Atlantic Ocean, and a review of paragnath morphology and methodology.

Pseudonereis gallapagensis Kinberg, 1865 and P. variegata (Grube Kröyer in Grube, 1858) are the only two species of this genus commonly recorded along Atlantic American coasts, but their type localities are in the Eastern Pacific, and their morphology differs. Two new Pseudonereis species are described from Eastern Mexico: P. brunnea sp. n. from the Gulf of Mexico, and P. citrina sp. n. from the Caribbean Sea, previously confused with P. gallapagensis. In order to facilitate comparisons, descriptions based on specimens from near the type locality for P. gallapagensis (Peru and Ecuador), and topotypes for P. variegata (Valparaiso, Chile), are included. Based on these comparisons and current descriptions, the synonymies of Nereis ferox Hansen, 1882 described from Brazil with P. variegata, and of Pseudonereis formosa Kinberg, 1865 described from Hawaii with P. gallapagensis, are rejected. Consequently, both are regarded as distinct species and revised diagnoses are provided for them. The record of P. ferox from the Gulf of Guinea proved to be an undescribed species, and is herein described as P. fauveli sp. n. The number of paragnath rows in nereidid pharynx areas VII-VIII has been interpreted in several ways, leading to confusion; an alternative method to determine the number of bands and rows is proposed. The midventral region, the division of areas VII-VIII in furrow and ridge regions, and the description of the arrangement based on the pattern of paragnaths in such regions, are proposed. Further, the terms shield-shaped and pointed (P-bars) bars are redefined, and a new term, crescent-shaped bars, is proposed for paragnaths in the areas VI in some Pseudonereis and Perinereis species. A key for all Pseudonereis species is also included.