20th International Congress of Arachnology

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DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
Student - oral presentation
Taxonomy, phylogeny and biogeography
of the Cytaea(Araneae: Salticidae) from
the Australasian Region
*Łukasz Trębicki 1, Barbara Patoleta1 , Yuri Marusik3,
Mirosława Dabert2, Marek Ż abka1
1Siedlce University of Natural Sciences and Humani-
ties, Department of Zoology, Prusa 12, 08-110,
Siedlce, Poland; 2Molecular Biology Techniques
Laboratory, Faculty of Biology, Adam Mickiewicz
University, Umultowska 89, 61-614 Poznan, Poland;
3Institute for Biological Problems of the North, Porto-
vaya Street 18, Magadan 685000, Russia
The main goals of the project are the following: 1) to
revise the genus Cytaea, 2) to distinguish species groups,
3) recognize speciation centres, 4) to present a complete
phylogeny and 5) distributional history of the genus,
including bioclimatic and phylogeographical models.
The genus Cytaea is distributed from SE Asia, through
Australia, New Guinea to New Caledonia and other W
Pacific archipelagos. It comprises 39 nominal species;
however, the real numbers are far from being complete as
during this project as many as 50 new species have been
found in Australia alone. According to recent molecular
and morphological data, the genus is a part of the tribe
Euophryini and is estimated to be some eighteen million
years old, with unclear origin area. The study, based on
types and new material, includes hundreds of specimens
and field records analysed using morphological (LM,
SEM, X-ray microtomography) and molecular data
(sequence data of COI, 28S rDNA, 16S-ND1 and Actin 5C
gene fragments). The findings are promising, largely sup-
porting results based on morphology and allowing us to
distinguish eight species-groups and to initially suggest
Australia-New Guinea as the genus’ biodiversity (origin?)
centre. So far, 12 nominal species have been re-studied (ŁT
& BP). New morphological characters for the genus, such
as “embolic teeth” and embolic accessory glands, have
been discovered. The latter not only have diagnostic value,
but are also potentially important in mating plug produc-
tion. Mating plugs have also been found in females.
Keywords: jumping spiders, molecular phylogenetics,
distribution, Australasia, mating plug, SEM
Oral presentation
Cascading increase of the chromosome
number showing concentric rings in Gagrel-
lula ferruginea (Arachnida: Opiliones) in
two different mountains in Japan
Nobuo Tsurusaki, Daichi Kawakami, Mizuho Yokoyama
Laboratory of Biology, Faculty of Regional Sciences,
Tottori University, Tottori, 680-855,1 Japan
Gagrellula ferruginea (Loman 1902) (Opiliones: Eupnoi:
Sclerosomatidae) is one of the most common species of
harvestmen in main islands of Japan except Hokkaido.
The species is diverse in coloration of body and at least 11
geographical forms have been recognized in the species.
The number of chromosomes of the species also varies
widely from 2n = 10 to 24, geographically. Populations of
the species with different chromosome numbers usually
integrate one another through a hybrid zone where chro-
mosome number is polymorphic including heterozygous
karyotypes whose chromosome numbers are odd. However,
sites where two forms with different colorations or differ-
ent number of chromosomes are sympatrically found have
been found at three different sites; two of them can be
interpreted as cases of circular overlap. Thus taxonomy of
the species is complicated and challenging. In the Tango
Mountains, northwestern part of Kyoto Prefecture, Honshu,
diploid number of chromosomes of the species abruptly
increase from 14 to 20 toward the center of the moun-
tains around Mt. Oye-yama from peripheral populations,
making a series of chromosomal hybrid zones. Karyotypic
analyses showed that a series of Robertsonian recipro-
cal translocations are responsible for the change and the
change proceeded successively from 2n=14 → 16 → 18
→ 20. On the other hand, a similar pattern of the increase
in the chromosome number through Robertsonian
translocations has recently been found in the Nunobiki
Mountains, in the middle part of Mie Prefecture, Honshu.
In the area, diploid number of chromosomes continuously
varies from 12 to 18 depicting a concentric scheme again.
20th International Congress of Arachnology