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Cladistic analysis of Segestriidae genera (Araneae, Synspermiata, Dysderoidea)

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André Marsola Giroti
Total Authors: 1
Document type: Doctoral Thesis
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
Defense date:
Examining board members:
Antonio Domingos Brescovit; Pedro Gnaspini Netto; Silvio Shigueo Nihei; Adalberto José dos Santos
Advisor: Antonio Domingos Brescovit

Amphibians possess a great diversity of skin glands, among which sexually dimorphic skin glands (SDSGs) are present in males and can form macroglands usually referred to as \"swollen\" regions. Dendrobatoidea is the only clade in which adult males present a swollen in finger IV supposedly associated with the cephalic amplexus, also exclusive to the superfamily. However, few studies of this character have been carried out and the histology of the structure has never been examined. We characterized the different morphologies of the swelling, assessed the anatomical distribution of its glands and tested its homology by taxonomic analysis. We studied the external and internal morphologies and the histology of the hands of adult males and females and juveniles of 27 species to compare all fingers and its gland types. To compare and describe the gland types found at the fingers we ran histochemical studies. We also analyzed the skin of the dorsum of dendobatoid frogs to determine if the gland types found at the swollen region were in fact SDSGs. Our findings showed typical serous and mucous glands at the dorsum and fingers of all individuals and we discovered specialized mucous glands of types I, II and III only at males with the swollen fourth finger. Type I glands are present in all males with the swelling, type II are restricted to Dendrobatidae and type III occur only in Anomaloglossus stepheni. We have also observed that males whose fourth finger was previously coded as \"without the swelling\" had in fact the swelling present, a fact corroborated by the presence of the specialized gland types. According to our samplings, the presence of the swelling in finger IV and of type I glands is a synapomorphy of Dendrobatoidea, with secondary absence at species without the swelling. The presence of type II glands is a synapomorphy of Dendrobatidae and the presence of type III glands is an autapomorphy of An. Stepheni. Our findings will guide studies in the most diverse fields such as dendrobatoid\'s reproductive behavior, biochemistry of glandular secretion and taxonomy (AU)