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International Journal of Marine Science 2015, Vol.5, No.3, 1-7
http://ijms.biopublisher.ca
1
Research Report Open Access
First report on mass reproductive swarming of a polychaete worm,
Dendronereis
aestuarina
(Annelida, Nereididae) Southern 1921, from a freshwater environment
in the south west coast of India
P.R. Jayachandran, M.P. Prabhakaran, C.V. Asha, Akhilesh Vijay, S. Bijoy Nandan
Department of Marine Biology, Microbiology & Biochemistry, School of Marine Sciences, Cochin University of Science & Technology, Cochin-16, India
Corresponding author email
International Journal of Marine Science, 2015, Vol.5, No.3 doi: 10.5376/ijms.2015.05.0003
Received: 25 Oct., 2014
Accepted: 23 Nov., 2014
Published: 05 Jan., 2015
Copyright
©
2015
Jayachandran et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Jayachandran et al., 2015, First report on mass reproductive swarming of a polychaete worm,
Dendronereis aestuarina
(Annelida, Nereididae) Southern 1921,
from a freshwater environment in the south west coast of India, International Journal of Marine Science, Vol.5, No.3 1
-
7 (doi
Abstract
In the present study we report the occurrence of red coloured mass reproductive swarms of
Dendronereis aestuarina
from
Periyar River of the south west coast of India. It was observed in the freshwater zone of the river during the evening hours of August
31
st
, 2010. Reproductive swarming
behaviour
of
D. aestuarina
has been first reported by Southern, 1921 from brackishwater
environment in the Gangetic delta, however present study reports first time from absolutely freshwater environment. The density of
swarmed polychaete was ~14800 indls. m
-2
with the average length of 86 ±16 mm. Male worms were dominated in the 60 specimens
analyzed and the sex ratio was 3:1 (M/F). The average diameter of eggs collected from polychaete body was 0.33 ± 0.08 mm.
Swarming was extended for two days; after successful mating and spawning they were died.
Keywords
Dendronereis aestuarina
; Reproductive swarming; Periyar River; Cochin estuary; Kodungallure - Azhikode estuary
Introduction
The polychaetes worms are generally found living in
all marine environments, some floating freely near the
surface or the bottom (pelagic fauna), some others, as
part of the benthic fauna, burrowing in the mud, sand
and rocks of seashores down to abyssal depths and
they can even colonize non marine habitats, such as
freshwater and others aquatic systems
. Over 10,000 species have
been described to date, belonging to 83 recognized
families, and various estimates have been made to the
total polychaete fauna ranging from 25,000 to 30,000
. They
exhibit considerable variations in recruitment both in
time and space, which is then often reflected in adult
distribution. The families and genera of polychaetes
have wide distributions while, normally, species have
discrete distributions
. A quantitatively enhanced
population indicates that input of organic matter
stimulates benthic productivity
.
They are involved in demineralization and recycling
processing of organic and inorganic matters in the
aquatic environment and energy flow through
different food chains
. The breeding
and spawning of polychaetes are induced by various
biotic and abiotic factors such as temperature,
endogenous and lunar timing, while swarming is
controlled by daytime, tide, environmental and
endocrine factors like pheromones
. Temperature is assumed to be
one of the most important external factors
synchronizing maturation and spawning in marine
invertebrates
.
The Nereididae
is among the most
diverse of polychaete families, comprising over 540
species and 43 genera
. They are
most common in shallow marine habitats, but the
Nereididae are the ones that have been more
commonly found in freshwater environments
compared to other polychaete families
. The variety of Nereididae species being
commercially harvested for fish bait and used as test
organisms in research related to physiology,
endocrinology and the environment