Dear Dr Richard Lord, regarding your query, at first look I suggest to
start with this paper in Marine Ecology and reference within....
all the best,
Maria Cristina Gambi
Life cycle of Marphysa sanguinea (Polychaeta: Eunicidae) in the Venice
Lagoon (Italy).
Daniela Prevedelli, Gloria Massamba N'Siala, Ivano Ansaloni & Roberto Simonini
Dipartimento di Biologia Animale, Università degli studi di Modena e
Reggio Emilia, Modena, Italy
Correspondence to Daniela Prevedelli: prevedelli.daniela from unimore.it
Abstract
The life cycle of a brackish water population of Marphysa sanguinea
(Polychaeta Eunicidae), from the Venice Lagoon (Italy), was
investigated from April 1993 to August 1994. Marphysa sanguinea is a
large-sized gonochoric species with annual iteroparous strategy and
synchronous spawning at population level. The sex-ratio was close to
1:1. There were no morphological differences between males and females
and spawning occurred without epitokal metamorphosis. The gonadial
activity was maximum during summer period in both sexes. From May to
September in the females, the greater number of immature oocytes could
be observed; starting from November immature oocytes decreased and
progressively those with a wider diameter increased in number.
Spawning took place in April?May and generally not all eggs were
spawned, a small proportion being kept as a reserve material for the
following gamete production. The pelagic phase (trochophore and
metatrochophore stages) was short (2?3 days). The reduction in the
dispersal phase, together with the development of a strong anterior
musculature, brought to an early acquisition of the benthic habit,
which was attained with the construction of the mucous tube inside of
which the larva lived. The results highlighted that colonization of
brackish environments took place thanks to morphological and
physiological features that allow this species to live in a sediment
layer characterized by the stability of the physical and chemical
characteristics of the substratum.
Citando Geoff Read <gread from actrix.gen.nz>:
> Posted on behalf of Richard Lord <fishinfo from guernsey.net>
>> G.
>> +++++++++++++++++++++++++++++++++++++++++++++++
> From: Richard Lord <fishinfo from guernsey.net>
> Date: 1 May 2009 14:31:50 BST
> To: annelida from magpie.bio.indiana.edu> Subject: Marphysa sanguinea life history
>> Over the last eight years I have witnessed heavy harvesting pressure
> of Marphysa sanguinea in local bays for use as fishing bait.
>> I would like to find out if the harvesting of Marphysa sanguinea in
> local bays is sustainable.
>> I would appreciate receiving general information on the life history
> and ecology of this species.
>> Some of the questions I am seeking answers for are:
>> What is the longevity of Marphysa sanguinea?
>> How old it is when it first breeds and how many years does it breed
> for?
>> How long do the larvae stay in the water column before settling to
> the sea bed and how widely dispersed can they be before settling to
> the bottom.
>> I wish to know whether transplanting of this species from nearby
> areas has been tried to repopulate a shore?
>> I have a photograph of the species here:
>http://www.smugmug.com/gallery/2074700_Fqi4W/1/107636133_pJKtM#107636133_pJKtM>> Large numbers of individuals are dug up in our local bays:
>http://www.sealordphotography.net/gallery/3514797_L9f6K#113230983_fMYSP>> Our specimens grow to a length of about 60 cm:
>http://www.sealordphotography.net/gallery/3514797_L9f6K#113230350_txHH2>> I have searched the Internet and found a few abstracts but I do not
> have a local library available to provide me with any journals.
>> Thank you for the help you can provide.
>> Best wishes,
>> Richard
>> Richard Lord
> Guernsey
> Channel Islands
>>fishinfo from guernsey.net> Tel: +44 (0)1481 700688
> Fax: +44 (0)1481 700686
>>http://www.sealordphotography.net>>>> _______________________________________________
> Annelida mailing list
> Post: Annelida from net.bio.net> Help/archive: http://www.bio.net/biomail/listinfo/annelida> Resources: http://www.annelida.net>
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
