The Systematic Position of the Archiannelida

Hermans, Colin O.

doi:10.2307/2412412

Cited by 54 publications

(26 citation statements)

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“…1988; Gardiner 1992). However, absence of circular muscle fibres occurs more often than is generally thought and several examples have been found in polychaetes including macrobenthic, meiobenthic, parapodia‐bearing as well as sedentary species of the following taxa: Opheliidae, Polygordiidae, Protodrilidae, Spionidae, Oweniidae, Aphroditidae, Acoetidae (= Polyodontidae), Polynoidae, Sigalionidae, Phyllodocidae, Nephtyidae, Pisionidae and Nerillidae (McIntosh 1917; Hartmann‐Schröder 1958; Orrhage 1964; Jouin and Swedmark 1965; Mettam 1967, 1971; Storch 1968; Hermans 1969; Gardiner and Rieger 1980; Tzetlin 1987; Ivanov and Tzetlin 1997). Absence of these fibres has also been reported for Jennaria pulchra , an enigmatic taxon with annelid affinities (Rieger 1991).…”

Section: Discussionmentioning

confidence: 99%

On the absence of circular muscle elements in the body wall of Dysponetus pygmaeus (Chrysopetalidae, ‘Polychaeta’, Annelida)

et al. 2002

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The annelid body wall generally comprises an outer layer of circular muscle fibres and an inner layer of longitudinal muscle fibres as well as parapodial and chaetal muscles. An investigation of Dysponetuspygmaeus (Chrysopetalidae) with confocal laser scanning microscopy showed that circular muscles are entirely absent. Further studies indicate that this feature is characteristic for all Chrysopetalidae. A scrutiny of the literature showed a similar situation in many other polychaetes. This lack of circular muscle fibres may either be due to convergence or represent a plesiomorphic character. Since circular muscles are very likely important for burrowing forms but not necessary for animals which proceed by movements of their parapodial appendages or cilia, this problem is also related to the question of whether the ancestral polychaete was epi‐ or endobenthic.

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Section: Discussionmentioning

confidence: 99%

On the absence of circular muscle elements in the body wall of Dysponetus pygmaeus (Chrysopetalidae, ‘Polychaeta’, Annelida)

et al. 2002

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“…Two cladistic analyses based on molecular data of 18S rDNA support the independent evolution of Parergodrilidae and Clitellata (Rota et al, 2001;Struck et al, 2002a). Struck et al (2002a) also found a relationship of Stygocapitella subterranea Kno¨llner, 1934 Hermans (1969) and the species (and genus) was considered invalid by Westheide (1990). A revision of Polygordius was made by Rota & Carchini (1999).…”

Section: Systematicsmentioning

confidence: 91%

“…Hatschek (1893) suggested that opheliids (classified with the Spiomorpha) were derived from saccocirrids that in their turn had evolved from polygordiids. A sister group within the Opheliidae has been reconsidered, based on similarities in the structure of cuticle, musculature and locomotion as well as by rejecting the interpretation of grooved palps (Hermans, 1969;Rouse & Pleijel, 2001). According to Westheide (1990), Polygordius is a rather isolated genus with no close affinity to Protodrilida.…”

Section: Systematicsmentioning

confidence: 99%

Evolution of interstitial Polychaeta (Annelida)

Worsaae

Kristensen

2005

Hydrobiologia

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An update of the systematics is given for the eight most important interstitial polychaete families: Diurodrilidae, Nerillidae, Protodrilidae, Protodriloididae, Saccocirridae, Parergodrilidae, Polygordidae and Psammodrilidae. Additional information and new observations are presented for the Diurodrilidae, Nerillidae and Psammodrilidae. Three new supplementary evolutionary hypotheses for these families are here suggested: (I) basal position of Diurodrilidae in Polychaeta, (2) evolution of Nerillidae in mud, and (3) evolution from meio-to macrofaunal forms of Psammodrilidae. Hydrobiologia (2005) 535

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“…The reproductive anatomy of both sexes was clearly described, and it was shown conclusively that females raised from the larval stage in isolation never contain sperm. The species ought to be reexamined in light of our more recent understanding of the origin of such a histological picture in Protodrilus (see Hermans, 1969b). Hence the sperm observed by the earlier authors are the result of insemination, not hermaphroditism.…”

Section: Hermaphroditismmentioning

confidence: 97%