Namalycastis occulta n. sp. and a new record of N. borealis (Polychaeta: Nereididae: Namanereidinae) from the Northwestern Caribbean Sea

Abstract

The nereidid polychaete genus Namalycastis Hartman, 1959 has been recorded almost exclusively in non-marine environments. This genus includes species having four pairs of tentacular cirri, and its species mainly differ by the relative size of dorsal cirri in posterior chaetigers. Namalycastis occulta n. sp. is described based upon non-mature and mature specimens collected in the intertidal from Chetumal Bay, Quintana Roo, Mexico. Its distinctive features are the lack of notopodial spinigers, eyes, and teeth in the mandibles. Namalycastis borealis Glasby was found in Tamalcab Island, Chetumal Bay and it is the first record for Mexico. Analyses of the intraspecific variability, a key to the known species in the Grand Caribbean region, and commentaries about some taxonomic topics are also included.

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss & Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919

“…However, the same troglomorphic features are present at least in one other epigean species from another genus living within mangrove leaves litter, Namalycastis occulta Conde-Vela, 2013, as already noted in a previous contribution (Conde-Vela 2013: 481). A recent phylogenetic study challenged the generic placement of this species, suggesting that N. occulta is more related to Namanereis than to any described Namalycastis, forming a strongly supported clade with Namanereis hummelincki (Alves and Santos 2016: 509-510).…”

“…In addition to the examined specimens, and in order to achieve an almost exhaustive discussion of the namanereidin morphology, all pertinent literature including original descriptions, revisions, notes about ecology and distribution, were taken into account. Morphological ratios and measurements used in some sections were obtained mainly from descriptions by Glasby (1999), and only from original descriptions for species described in other publications (Glasby 1997, Fiege and Van Damme 2002, Magesh et al 2012, Conde-Vela 2013, Magesh et al 2014, Alves and Santos 2016. Only ratios of type material were included and, if a range was declared, the average was used; if not clearly stated in descriptions, measures for ratios were obtained from illustrations.…”

“…4A), and even the first four species (including N. araps) have jointed tentacular cirri (Glasby 1997(Glasby , 1999, but this feature cannot be regarded exclusively as an adaptation to subterranean habitats, because it is also present in epigean species such as Namalycastis elobeyensis, N. indica and N. kartaboensis (Glasby 1999), and even outside namanereidins. All Namalycastis and epigean Namanereis with clear elongation of upper neuropodial falcigers occur in freshwater or brackish environments as ponds, streams and estuaries, and in muddy to sandy sediments (Glasby 1999, Conde-Vela 2013, Alves and Santos 2016, but not in subterranean habitats.…”

The Nereididae (Annelida) – diagnoses, descriptions, and a key to the genera

“…Since Glasby (1999) there have been five species described: Namalycastis caetensis Alves & Santos, 2016, Namalycastis glasbyi Fernando & Rajasekaran, 2007, Namalycastis jaya Magesh, Kvist & Glasby, 2012, Namalycastis occulta Conde-Vela, 2013 and Namalycastis rhodochorde Glasby, Miura, Nishi & Junardi, 2007; however, Namalycastis occulta Conde-Vela, 2013 is now accepted as Namanereis occulta (Conde-Vela, 2013). Magesh et al (2013) provided a key to Indian species and Conde-Vela (2013) provided a key to Caribbean species.…”

Incipient speciation within the Namalycastis abiuma (Annelida: Nereididae) species group from southern India revealed by combined morphological and molecular data

“…Thirty-nine namanereidin species have been reported throughout the world and some of these pertain to larger complexes of problematic species, herein termed "species groups". The genus Namalycastis contains 22 species (Glasby 1999a(Glasby , 1999bMagesh et al 2012;Conde-Vela 2013), four of which have so far been recorded on the Indian subcontinent. These include N. indica Southern, 1921, N. fauveli Nageswara Rao, 1981, N. glasbyi Fernando & Rajasekaran, 2007, and N. jaya Magesh, Kvist & Glasby, 2012.…”