Origins of holopelagic Typhloscolecidae and Lopadorhynchidae within Phyllodocidae (Phyllodocida, Annelida)

Abstract

Struck, T. H. & Halanych, K. M. (2010). Origins of holopelagic Typhloscolecidae and Lopadorhynchidae within Phyllodocidae (Phyllodocida, Annelida).-Zoologica Scripta, 39, 269-275. Several distinct lineages of annelids have evolved holopelagic life styles. Unfortunately, our knowledge of the biology and evolution of most of these groups is limited. Typhloscolecidae and Lopadorhynchidae are two such examples of recognized families of holopelagic annelids about which little is known.Both groups have a limited number of known species (13 and 15, respectively) and are rarely discussed in the literature other than to note occurrence. Placing these groups in a phylogenetic context has been difficult due to their seemingly unique morphology, and, to the best of our knowledge, lack of molecular data. Nonetheless, previous authors have suspected that they are members of Phyllodocida and perhaps within Phyllodocidae. To test such hypotheses, we have employed nuclear 18S and 28S ribosomal data in both a Bayesian inference and a maximum-likelihood framework. The resultant topology indicates that typhloscolecids and lopadorhynchs are sister taxa nested within Phyllodocidae near another holopelagic taxon, alciopids. Whereas posterior probabilities strongly support this placement, an AU hypothesis testing approach and bootstrap values are more equivocal but both still strongly suggest Phyllodocidae affiliations. Recognition of Typhloscolecidae and Lopadorhynchidae as annelid families is called into question.

Phylogenetic hypothesis of Sphaerodoridae Malmgren, 1867 (Annelida) and its position within Phyllodocida

“…Monophyly, circumscription and potential synapomorphies of Phyllodocida have been extensively debated ; and references therein), especially in the last two decades, mainly due to the assessment of the position of the aberrant Myzostomida and other symbiotic annelids (e.g. Eeckhaut et al, 2000;Zrzav y et al, 2001Zrzav y et al, , 2009Bleidorn et al, 2007Bleidorn et al, , 2009Bleidorn et al, , 2014Struck et al, 2008Struck et al, , 2011Hartmann et al, 2012;Aguado et al, 2013;Kvist and Siddall, 2013;Struck, 2013;Weigert et al, 2014). Phyllodocida has mostly been considered monophyletic, defined by the presence of an axial, muscular pharynx (e.g.…”

“…Rouse and Pleijel, 2001). Recent studies dealing with the delineation and phylogenetic relationships of members of Phyllodocida are Rouse and Pleijel (2001), Halanych et al (2007), Rousset et al (2007), Struck et al (2007Struck et al ( , 2011, Struck and Halanych (2010), Norlinder et al (2012), Aguado et al (2013) and Weigert et al (2014), among others.…”

Chimaeras and the origins of the holopelagic annelids Typhloscolecidae and Lopadorhynchidae: a reply to Struck & Halanych (2010)

“…2007), although their exact position remains uncertain. Based on analyses of nuclear 18S and 28S sequences, Struck & Halanych (2010) in a recent paper in this journal stated that also the families Typhloscolecidae and Lopadorhynchidae belong within the phyllodocids. They presented a topology where typhloscolecids and lopadorhynchids together form a clade that is closely related to alciopids with a sister group relationship within the Phyllodocidae.…”

“… To the left is the original maximum‐likelihood tree of the 28S and 18S analysis from Struck & Halanych (2010) (−ln L = 28 964.30), to the right is the maximum‐likelihood tree for the same dataset except for the excised region of the 28S of Phyllodoce groenlandica 2 sequence (−ln L = 28 253.23). Bootstrap values above 50 and posterior probability values equal to or above 0.95 are shown.…”

An oral brush of cilia in the feeding larvae of Micronephtys cornuta (Annelida, Nephtyidae)

“…This article is protected by copyright. All rights reserved Aphroditiformia and Nephtyidae (Pleijel and Dahlgren 1998;Struck and Halanych 2010). Even if the two groups are not closely related within Phyllodocida, the oral brushes of the two taxa may be homologous.…”