Previous Page  195 / 232 Next Page
Information
Show Menu
Previous Page 195 / 232 Next Page
Page Background

that while females made predicted choices when male

traits covaried positively, in negative covariance (cue-

conflict) choice tests, females showed a bias for higher

male quality in visual signals. Female wolf spiders

therefore appear to exhibit comparative mate evalua-

tion of individual signal modes in multimodal signals,

and assess male quality among potential suitors.

Keywords: behavior, communication, vibratory signals,

video playback, Lycosidae

Oral presentation

Securing paternity by mutilating female

genitalia in spiders

Gabriele Uhl, Pierick Mouginot, Philip O. M. Steinhoff

University of Greifswald, Zoological Institute and

Museum, General and Systematic Zoology, Germany

gabriele.uhl@uni-greifswald.de

Competition between males and their sperm over access to

females and their eggs has resulted in manifold ways by

which males try to secure paternity, ranging from physi-

cally guarding the female after mating to reducing her

receptivity or her attractiveness to subsequent males by

transferring manipulative substances or by mechanically

sealing the female reproductive tract with a copulatory

plug. Copulations may also result in internal damage

of the female genitalia; however, this is not considered

as a direct adaptation against sperm competition but as

a collateral effect. Here, we present a drastic and direct

mechanism for securing paternity: the removal of coupling

structures on female genitalia by males. In the orb-weav-

ing spider

Larinia jeskovi

males remove the scapus, a

crucial coupling device on the female external genital

region. Reconstruction of the coupling mechanism using

micro-CT-scanned mating pairs revealed that several scler-

ites of the male genitalia interact to break off the scapus.

Once it is removed, remating cannot occur due to mechan-

ical coupling difficulties. In the field, male-inflicted genital

damage is very prevalent since all female

L. jeskovi

were

found to be mutilated at the end of the mating season.

External genital mutilation is an overlooked but widely

spread phenomenon since 80 additional spider species

were found for which male genital manipulation can be

suspected. Interlocking genitalia provide an evolutionary

platform for the rapid evolution of this highly effective

mechanism to secure paternity, and we suspect that other

animal groups with interlocking genital structures might

reveal similarly drastic male adaptations.

Keywords: sexual selection, conflict, securing paternity,

functional morphology of genitalia

Oral presentation

A molecular phylogenetic approach to the

New Zealand species of Enantiobuninae

(Opiliones: Eupnoi : Neopilionidae)

Sebastián Vélez

1,2

, Rosa Fernández

2

, Gonzalo Giribet

2

1

Biology Department, Worcester State University,

Worcester, Massachusetts, USA;

2

Museum of Com-

parative Zoology, Department of Organismic and

Evolutionary Biology, Harvard University, 26 Oxford

Street, Cambridge, Massachusetts, USA

svelez@worcester.edu

We report the first phylogeny based on molecular data for

the New Zealand species in the genera

Forsteropsalis, Pan-

topsalis

, and

Mangatangi

, and comment on the taxonomic

implications of our results, including the diagnostic viability

of important morphological characters. Members of the New

Zealand Enantiobuninae constitute some of the most char-

ismatic soil arthropods of the archipelago, and a striking

example of sexual dimorphism, with nondescript females but

colourful males boasting exaggerated chelicerae many times

longer than their bodies. The genera

Forsteropsalis

and

Pantopsalis

recently underwent revision, but many questions

remained about the validity of many species designations,

due to issues of characters of dubious taxonomic value,

female specimens designated as holotypes despite the males

holding all the diagnostic characters, and the suspected pres-

ence of more than one male form within some species. We

present the first molecular phylogenetic study of the group,

including extensive sampling of fresh material across New

Zealand. Our results reject the controversial monophyly of

Neopilionidae and comment on the taxonomic implications

of the results, including the diagnostic validity of mor-

phological characters traditionally used on the groups.

Keywords: Opiliones, Australia, biogeography, phylogeny

194

DENVER MUSEUM OF NATURE & SCIENCE

REPORTS

|

No. 3, July 2, 2016

Cushing