Reproductive biology of the intertidal spider Desis marina (Araneae: Desidae) on a New Zealand rocky shore

• Published in: Journal of Zoology
• Main Authors: MCLAY, C. L., HAYWARD, T. L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1987
• Subjects: New Zealand; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1111/j.1469-7998.1987.tb01539.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1987.tb01539.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1987.tb01539.x; https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1987.tb01539.x

Desis marina is an intertidal spider which lives within rock crevices and cavities in the holdfasts of the brown kelp Durvillaea antarctica , where it is submerged in the sea for long periods. Spiders live within silk‐lined retreats which enclose an air bubble, and mate location is restricted to periods when the nest is exposed to the air. Eggs are laid from September to January and emergence is complete by May, with the major recruitment period being from March to April. During June to August, females are reproductively inactive. Egg development requires two months and the first two instars remain in the nest for a further two months. Number of egg sacs laid is independent of female size but number of eggs per sac increases with size. Egg size and number of eggs per sac is independent of brood sequence. Female reproductive investment is only 17–6% of body weight, but with 3 to 4 egg sacs/female, nest‐guarding time is in excess of five months. Females reproduce only once per year and may reproduce again in the following summer. Desis marina has a much lower clutch size than comparable terrestrial spiders and is a ‘bet‐hedger’, producing sequential broods which spread recruitment over time and reduce the risk of total loss due to storms.