Description of six new species of Mesonerilla (Nerillidae, Annelida) and an emended description of M. intermedia Wilke, 1953, from marine and cave environments

TY - JOUR

T1 - Description of six new species of Mesonerilla (Nerillidae, Annelida) and an emended description of M. intermedia Wilke, 1953, from marine and cave environments

AU - Worsaae, Katrine

AU - Mikkelsen, Maria Damsgaard

AU - Martínez, Alejandro

PY - 2019

Y1 - 2019

N2 - Nerillidae is a species-rich family of meiofaunal, mainly interstitial annelids. The genus Mesonerilla previously contained eight described species. We here describe six new species of Mesonerilla based on detailed morphological light and scanning electron microscopy studies. The new species were collected from coastal subtidal and tidal sediments, as well as from anchialine caves, in the Mediterranean, Canary Islands, Panamá, Trinidad and Tobago and the USA. All species of Mesonerilla contain nine segments, two-three antennae, two club-shaped palps, parapodial cirri and compound chaetae in most segments. New species are diagnosed by unique character traits and/or a unique combination of characters involving differences in shape of appendages, reproductive characters and glandular and ciliary patterns. Their validation is further supported by a molecular phylogeny including these and the majority of described species of Mesonerilla. With most of the diagnostic characters of the described species being hardly discernible, and with potential additional molecular identifiable species left undescribed, the genus Mesonerilla, as many other interstitial groups, show a high degree of cryptic diversity.

AB - Nerillidae is a species-rich family of meiofaunal, mainly interstitial annelids. The genus Mesonerilla previously contained eight described species. We here describe six new species of Mesonerilla based on detailed morphological light and scanning electron microscopy studies. The new species were collected from coastal subtidal and tidal sediments, as well as from anchialine caves, in the Mediterranean, Canary Islands, Panamá, Trinidad and Tobago and the USA. All species of Mesonerilla contain nine segments, two-three antennae, two club-shaped palps, parapodial cirri and compound chaetae in most segments. New species are diagnosed by unique character traits and/or a unique combination of characters involving differences in shape of appendages, reproductive characters and glandular and ciliary patterns. Their validation is further supported by a molecular phylogeny including these and the majority of described species of Mesonerilla. With most of the diagnostic characters of the described species being hardly discernible, and with potential additional molecular identifiable species left undescribed, the genus Mesonerilla, as many other interstitial groups, show a high degree of cryptic diversity.

KW - Anchialine fauna

KW - Interstitial

KW - Meiofauna

KW - Microscopy

KW - Molecular phylogeny

U2 - 10.1007/s12526-019-00984-6

DO - 10.1007/s12526-019-00984-6

M3 - Journal article

AN - SCOPUS:85074498628

SN - 1867-1616

VL - 49

SP - 2141

EP - 2165

JO - Marine Biodiversity

JF - Marine Biodiversity

IS - 5

ER -