The University of Southampton
University of Southampton Institutional Repository

Reproductive ecology of the circumpolar Antarctic nemertean Parborlasia corrugatus: No evidence for inter-annual variation

Reproductive ecology of the circumpolar Antarctic nemertean Parborlasia corrugatus: No evidence for inter-annual variation
Reproductive ecology of the circumpolar Antarctic nemertean Parborlasia corrugatus: No evidence for inter-annual variation
Waters around the Antarctic Peninsula are experiencing one of the fastest rates of warming seen anywhere on Earth in the sea in recent times. Species inhabiting nearshore seabed sites in Antarctica have a long history in near freezing temperatures and have poor physiological capacities to cope with change. Reproductive success is a vital characteristic in species survival and evaluation of how reproductive processes vary with time is key to identifying vulnerable species and evaluating the effects of ocean warming.

The long-term gametogenic development of the nemertean Parborlasia corrugatus (McIntosh, 1876) was analysed from monthly samples collected between July 1997 and November 2000 from a shallow water site adjacent to the British Antarctic Survey Rothera Research Station (Western Antarctic Peninsula). Spermatogenesis, oocyte size and reproductive condition are described for each month using histological and image analysis techniques. Male and female reproductive condition varied seasonally, with a reduction in the proportion of large oocytes and mature sperm in the gonad during the late austral summer (December–March). We identify three key characteristics in the reproductive ecology of P. corrugatus (1) the timing of reproduction was consistent in the late austral summer of each year and synchronous between males and females (2) oogenesis progressed over a discrete 15–16 month period with a single generation of oocytes in the ovary during most stages of gametogenic development and (3) notable differences in reproductive condition were not apparent from year to year. The majority of long-term studies on reproductive ecology of marine invertebrates at high latitudes, with the exception of one or two species, revealed that 18–24 months are required for gametogenesis compared to 6–12 months in temperate species and there is extreme inter-annual variation in reproductive output. P. corrugatus differs from this in requiring only 15 months for gametogenesis, and has little or no variation between years. This may be because of its predatory lifestyle and that coupling between its gametogenic development and timing, and larval abundance and nutrition with phytoplankton productivity is much less than in the previously studied Antarctic marine herbivores and omnivores. However, the timing of larval settlement and peak juvenile abundance in P. corrugatus does suggest coupling with seasonal productivity through the nemertean's larval and juvenile ecology.
Antarctica, Environmental change, Gametogenesis, Predator, Reproductive condition, Seasonality
0022-0981
98-107
Grange, L.J.
8de65684-8e14-4cc2-89d1-ca20322714e4
Peck, Lloyd S.
097d27ed-4644-4bc1-a855-045029ace2df
Tyler, Paul A.
d1965388-38cc-4c1d-9217-d59dba4dd7f8
Grange, L.J.
8de65684-8e14-4cc2-89d1-ca20322714e4
Peck, Lloyd S.
097d27ed-4644-4bc1-a855-045029ace2df
Tyler, Paul A.
d1965388-38cc-4c1d-9217-d59dba4dd7f8

Grange, L.J., Peck, Lloyd S. and Tyler, Paul A. (2011) Reproductive ecology of the circumpolar Antarctic nemertean Parborlasia corrugatus: No evidence for inter-annual variation. Journal of Experimental Marine Biology and Ecology, 404 (1-2), 98-107. (doi:10.1016/j.jembe.2011.04.011).

Record type: Article

Abstract

Waters around the Antarctic Peninsula are experiencing one of the fastest rates of warming seen anywhere on Earth in the sea in recent times. Species inhabiting nearshore seabed sites in Antarctica have a long history in near freezing temperatures and have poor physiological capacities to cope with change. Reproductive success is a vital characteristic in species survival and evaluation of how reproductive processes vary with time is key to identifying vulnerable species and evaluating the effects of ocean warming.

The long-term gametogenic development of the nemertean Parborlasia corrugatus (McIntosh, 1876) was analysed from monthly samples collected between July 1997 and November 2000 from a shallow water site adjacent to the British Antarctic Survey Rothera Research Station (Western Antarctic Peninsula). Spermatogenesis, oocyte size and reproductive condition are described for each month using histological and image analysis techniques. Male and female reproductive condition varied seasonally, with a reduction in the proportion of large oocytes and mature sperm in the gonad during the late austral summer (December–March). We identify three key characteristics in the reproductive ecology of P. corrugatus (1) the timing of reproduction was consistent in the late austral summer of each year and synchronous between males and females (2) oogenesis progressed over a discrete 15–16 month period with a single generation of oocytes in the ovary during most stages of gametogenic development and (3) notable differences in reproductive condition were not apparent from year to year. The majority of long-term studies on reproductive ecology of marine invertebrates at high latitudes, with the exception of one or two species, revealed that 18–24 months are required for gametogenesis compared to 6–12 months in temperate species and there is extreme inter-annual variation in reproductive output. P. corrugatus differs from this in requiring only 15 months for gametogenesis, and has little or no variation between years. This may be because of its predatory lifestyle and that coupling between its gametogenic development and timing, and larval abundance and nutrition with phytoplankton productivity is much less than in the previously studied Antarctic marine herbivores and omnivores. However, the timing of larval settlement and peak juvenile abundance in P. corrugatus does suggest coupling with seasonal productivity through the nemertean's larval and juvenile ecology.

Full text not available from this repository.

More information

Published date: 31 July 2011
Keywords: Antarctica, Environmental change, Gametogenesis, Predator, Reproductive condition, Seasonality

Identifiers

Local EPrints ID: 191689
URI: http://eprints.soton.ac.uk/id/eprint/191689
ISSN: 0022-0981
PURE UUID: 22cd1890-3f5d-4a24-ac80-10aeeef7cd0c
ORCID for L.J. Grange: ORCID iD orcid.org/0000-0001-9222-6848

Catalogue record

Date deposited: 23 Jun 2011 13:20
Last modified: 19 Nov 2019 01:35

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×