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The circulatory system in Chilopoda: functional morphology and phylogenetic aspects
Author(s) -
Wirkner Christian S.,
Pass Günther
Publication year - 2002
Publication title -
acta zoologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.414
H-Index - 37
eISSN - 1463-6395
pISSN - 0001-7272
DOI - 10.1046/j.1463-6395.2002.00112.x
Subject(s) - circulatory system , biology , anatomy , synapomorphy , ultrastructure , phylogenetic tree , endocrinology , clade , biochemistry , gene
The circulatory organs of nine representative species of all five chilopod orders were examined by light microscopy and by in vivo observations of haemolymph flow. In Scutigera coleoptrata , the heart ultrastructure was studied. The circulatory system in Craterostigmomorpha is described for the first time. Further focus is placed on the Geophilomorpha since previous descriptions in this group have been only superficial. In all investigated species, the circulatory system consists of two longitudinal central vessels which are connected in the first body segment by the maxilliped arch. The posterior part of these vessels is contractile and thus haemolymph is pumped anteriorly in the heart, while it is pumped posteriorly in the supraneural vessel. From these central vessels numerous peripheral vessels branch off. Differences among the chilopod orders lie mainly in the distribution of the peripheral vessels. The circulatory system in Scutigeromorpha shows some striking morphological adaptations with regard to the functional coupling of circulatory and respiratory tasks. The most peculiar structures are the aortic diverticles which act as accessory pumps in the head. Phylogenetic analysis of the circulatory organ traits within Chilopoda supports the Pleurostigmophora hypothesis. Synapomorphies supporting the Myriapoda hypothesis or the Tracheata concept were not found.