Copulatory Behavior and Web of Indicoblemma Lannaianum From Thailand (Arachnida, Araneae, Tetrablemmidae)

Abstract

ABSTRACT. The present study reports for the first time on the behavior prior to, during and after the copulation of a member of the haplogyne spider family, Tetrablemmidae and describes the web of this species. Prior to copulation, male and female of Indicoblemma lannaianum from Thailand sometimes avoided each other or the female scared the male away, apparently by vigorous vibrations of her body. When first copulations were initiated, they lasted from 1.21 to 3.8 h with an average of 2.25 Ϯ 0.71 h (n ϭ 17). Some females accepted a second male for mating 3-9 days after first mating. There was no significant difference between the duration of first and second copulations but significantly more trials were needed to induce the second copulations. In the copulatory position, the male was inverted and faced in the same direction as the female. He seized the female's opisthosoma with apophyses on his chelicerae which fit into grooves on a female's ventral plate in this way building a locking mechanism during copulation. The pedipalps were inserted alternately. The web of I. lannaianum consisted of a longish narrow sheet, which was made of many short threads forming a zigzag pattern and additional long oblique threads overdrawing the sheet and functioning as signal threads.

Complex genital system of a haplogyne spider (Arachnida, Araneae, Tetrablemmidae) indicates internal fertilization and full female control over transferred sperm

“…The assumption of first male sperm priority is supported by the copulatory behavior of the spiders. Females become distinctively reluctant to copulate a second time after their first copulation (Burger et al, 2006), which indicates that they become choosier with increasing copulation numbers, as suggested by Schä -fer and Uhl (2002) for Pholcus phalangioides. However, more knowledge of female mating and oviposition histories is necessary to clarify a possible sperm priority pattern.…”

“…As described by Burger et al (2006), the male uses apophyses on his chelicerae to grasp grooves on the preanal plate of the female's opisthosoma, in this way building an efficient locking mechanism during copulation. The present study includes Figures 19 and 20, which illustrate that the apophyses are provided with fine lengthwise ridges that should enable an enhancement of the locking.…”

Copulatory and Post-copulatory Sexual Selection in Haplogyne Spiders, with Emphasis on Pholcidae and Oonopidae

“…Additionally, the reproductive biology of spiders is unusual, that make them compelling aims for studies on sperm competition and CFC (Eberhard 2004). The highly complex female genital morphology of some species suggests that females play active roles in processes associated with receiving, storing, and dumping sperm (Burger 2007;Burger et al 2003Burger et al , 2006a. In addition, mating behavior observations in combination with a thorough investigation of the genital morphology in spiders show large potential consequences for understanding the reproductive biology of particular species (Burger 2007;Huber 1994Huber , 1995Huber and Eberhard 1997;Uhl et al 1995).…”

Functional genital morphology of armored spiders (Arachnida: Araneae: Tetrablemmidae)

“…Males of Ablemma unicornis bear a tooth on the carapace and females show a corresponding pit on the sternum. If the copulatory position in A. unicornis is the same as in Indicoblemma lannaianum (see Burger et al, 2006c) and Monoblemma muchmorei (see Edwards and Edwards, 2006) it is hard to imagine how the spine remains locked to the female's sternum during copulation. However, males of I. lannaianum sometimes push the female back prior to copulation (Burger et al, 2006c).…”

“…Schwendinger (1989Schwendinger ( , 1994 collected and observed several pacullines, Burger et al (2006c) described web and mating behavior of the tetrablemmine Indicoblemma lannaianum, and Edwards and Edwards (2006) observed the life history of Monoblemma muchmorei. The only detailed morphological investigation of a female tetrablemmid genital system was by Burger et al (2006a).…”