IngentaConnect Phylogenetic analysis of anostracans (Branchiopoda: Anostraca) in...

Abstract:

The nuclear small subunit ribosomal DNA (18S rDNA) of 27 anostracans (Branchiopoda: Anostraca) belonging to 14 genera and eight out of nine traditionally recognized families has been sequenced and used for phylogenetic analysis. The 18S rDNA phylogeny shows that the anostracans are monophyletic. The taxa under examination form two clades of subordinal level and eight clades of family level. Two families the Polyartemiidae and Linderiellidae are suppressed and merged with the Chirocephalidae, of which together they form a subfamily. In contrast, the Parartemiinae are removed from the Branchipodidae, raised to family level (Parartemiidae) and cluster as a sister group to the Artemiidae in a clade defined here as the Artemiina (new suborder). A number of morphological traits support this new suborder. The Branchipodidae are separated into two families, the Branchipodidae and Tanymastigidae (new family). The relationship between Dendrocephalusand Thamnocephalus requires further study and needs the addition of Branchinella sequences to decide whether the Thamnocephalidae are monophyletic. Surprisingly, Polyartemiella hazeni and Polyartemia forcipata(“Family” Polyartemiidae), with 17 and 19 thoracic segments and pairs of trunk limb as opposed to all other anostracans with only 11 pairs, do not cluster but are separated by Linderiella santarosae(“Family” Linderiellidae), which has 11 pairs of trunk limbs. All appear to be part of the Chirocephalidae and share one morphological character: double pre-epipodites on at least part of their legs. That Linderiellais part of the Polyartemiinae suggests that multiplication of the number of limbs occurred once, but was lost again in Linderiella. Within Chirocephalidae, we found two further clades, theEubranchipus–Pristicephalus clade and the Chirocephalusclade. Pristicephalus is reinstated as a genus.

Language: English

Document Type: Research article

DOI: 10.1016/S1055-7903(02)00289-0

Affiliations: 1: Department of Biology, Ghent University, Ledeganckstraat 35, B-9000 Ghent, Belgium 2: Biology Department, Our Lady of the Lake University of San Antonio, San Antonio, TX 78207, USA

The full text electronic article is available for purchase. You will be able to download the full text electronic article after payment.

$54.13 plus tax Refund Policy

Phylogenetic analysis of anostracans (Branchiopoda: Anostraca) inferred from nuclear 18S ribosomal DNA (18S rDNA) sequences