10.5061/DRYAD.J0ZPC86C0
Green, Leon
0000-0002-3328-3655
University of Gothenburg
University of Gothenburg
Niemax, Jan
University of Hamburg
Herrmann, Jens‐Peter
Universität Hamburg
Temming, Axel
0000-0002-0653-0614
Universität Hamburg
Kvarnemo, Charlotta
0000-0001-8983-2900
University of Gothenburg
Supplementary data to “Alternative reproductive tactics are associated
with sperm performance in invasive round goby from two different salinity
environments”
Dryad
dataset
2020
Ecological Experiment
natural history
Evolutionary and Behavioral ecology
Neogobius melanostomus
Spermatozoa
Animal physiology
Marine and estuarine ecology
Freshwater ecology
Swedish Research Council
https://ror.org/03zttf063
2016‐03343
2022-01-29T00:00:00Z
2022-01-29T00:00:00Z
en
https://doi.org/10.1002/ece3.6657
44808 bytes
3
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
During male-male competition, evolution can favor alternative reproductive
tactics. This often results in a dominant morph that holds a resource,
such as a nest for egg laying, competes with a smaller sneaker morph that
reproduces by stealing fertilizations. The salinity environment can
influence male growth rates, e.g. via osmoregulatory costs, which in turn
may influence the use of sneaker tactics for small males competing for
mating opportunities. Salinity can also affect sperm directly; however,
little is known of how salinity influences sneaker tactics through sperm
performance. We sampled males of the invasive round goby (Neogobius
melanostomus) from two environments, a freshwater river and a brackish
estuary. This fish has two male morphs: nest-holding dark males and
non-nest-holding light males. We examined the role of water salinity of 0,
8 and 16 on sperm performance and found that in estuarine males, a
salinity of 0 reduced sperm velocity compared to a salinity of 8 and 16.
Riverine males had low velocity in all salinities. Sperm viability also
decreased by over 30 % in 0 salinity, compared to 8 and 16, for fish from
both environments. Gobies produce ejaculate contents in specialized glands
that could in theory shield sperm in an adverse environment. However,
gland contents did not improve sperm performance in our tests. Body mass
and age estimates indicate that riverine males invested more in somatic
growth compared to estuarine males. Estuarine light morph males had a high
enough gonadosomatic index to indicate sneaker tactics. We propose that
when sperm performance is low, such as for the riverine males, sneaker
tactics are ineffective, and will be selected against or phenotypically
suppressed. Instead, we interpret the increased investment in somatic
growth found in riverine males as a life-history decision that is
advantageous when defending a nest in the next reproductive season.
Please see manuscript for an extensive description of data collection.
Physiological data from Neogobius melanostomus sampled from a river and a
brackish estuary in 2017.
Please see Readme.rtf file for information. Data stored and published
under Creative Commons.