A Biosystematic Revision of the Endemic Orbweaver Genus Zealaranea Court & Forster, 1988 (Araneidae: Araneae)

Abstract

This thesis conducts a comprehensive analysis of the endemic orbweaver genus Zealaranea Court & Forster, 1988 encompassing both molecular phylogenetic and morphological methods to review the taxonomy of the genus and the four current species. The molecular approach utilised mitochondrial DNA cytochrome oxidase I (COI) sequences from Zealaranea crassa (Walckenaer, 1841), Z. prina Court & Forster, 1988 & Z. trinotata Court & Forster, 1988 n = 27) and the morphological review included examination of overall morphology and reproductive morphology of Z. crassa, Z. trinotata, Z. prina, and Z. saxitalis (Urquhart, 1891). The phylogenetic analysis was conducted using both Maximum Likelihood (ML) and Maximum Parsimony (MP) methods, revealing two distinct clades: one including Z. prina specimens, and another incongruent clade with Z. crassa and Z. trinotata. Despite these incongruities, the composite index indicated a good fit with COI sequences, suggesting the reliability of the results. PERMANOVA results affirmed significant interspecies genetic variability, thus supporting the placement of Z. prina as a separate clade in the M L tree. The pairwise distance matrices showed an average observed distance between all species, which decreased upon exclusion of Z. prina, indicating potential sequence issues or low inter specific variation in the amplified COI region. Following the molecular phylogenetic analysis, a morphological revision was undertaken with over 140 specimens , including type specimens when possible . Distinct reproductive biology and minor morphological differences unique to each species affirmed the taxonomic validity o f Z. trinotata, Z. crassa, and Z. prina. These differences were notably observed in the reproductive structures, including the female epigynum and the male pedipalp structure, where the median apophysis emerged as a critical diagnostic characteristic. Z. s axitalis is proposed to be labelled as nomen dubium, due to its classification based on immature specimens from the late 1800s, and the lack of subsequent collections. Although COI clades provided limited taxonomic resolution, they offered a starting point , highlighting the need for a more comprehensive analysis.