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1
Beijing Wokshop, September 2002 Larval food
(Artemia), larviculture and ecotoxicology group
(UE partner 4) Members Dr. Francisco
Amat Dr. Francisco Hontoria Dr. Juan Carlos
Navarro Dr. Inmaculada Varó Óscar
Monroig Germán Medina Olga Ruiz
Instituto de Acuicultura de Torre de la Sal
Consejo Superior de Investigaciones Científicas
12595 Ribera de Cabanes (Castellón)
SPAIN
2
  • Distribution of A. persimilis and A. franciscana
    populations in Argentina
  • Presence of rare males in diploid parthenogenetic
    Artemia populations from the Old World
  • Updating of cyst bank and database

3
  • Distribution of A. persimilis and A. franciscana
    populations in Argentina (1)
  • Presence of Artemia franciscana North of 36º S
    and A. persimilis South of 37º S.
  • The population of A. franciscana from Las Tunas
    lagoon (33º 44S) evidences a phenomenon of
    hybridisation or introgression 50 males show
    n22 chromosomes, and 50 n21 chromosomes.
  • Laboratory crossbreeding experiments show
    reproductive isolation between A. franciscana
    (Mar Chiquita, Las Tunas) and A. persimilis
    (Salinas Grandes de Hidalgo) Argentinean
    populations.
  • Laboratory population from Las Tunas crossbreeds
    with Mar Chiquita (A. franciscana) population,
    and does not with Salinas Grandes de Hidalgo (A.
    persimilis) population.

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Females
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Males
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  • Distribution of A. persimilis and A. franciscana
    populations in Argentina (2)
  • Laboratory populations from A. franciscana and A.
    persimilis in competition show different
    reproductive output in terms of
    oviparism/ovoviviparism.
  • Under suboptimal conditions of food availability
    A. persimils shifts immediately to oviparism,
    while A. franciscana always keeps moderate levels
    of ovoviviparism (gt 13 )
  • Under the same conditions (environmental, food
    availability) co-occurring populations from both
    species show different reproductive output. A.
    franciscana females show always higher fecundity
    than A. persimilis females.
  • Former results explain a competitive development
    under which A. franciscana population outcompetes
    completely A. persimilis .

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  • Presence of rare males in diploid parthenogenetic
    Artemia populations from the Old World (1)
  •  
  • Rare males were found in 22 populations of
    Artemia parthenogenetica (diploid) from the Old
    World 9 populations in the Iberian peninsula
    (Spain and Portugal), 2 populations from Africa
    (Namibia and Egypt), and 11 populations from
    Eurasia (Italy, Ukraine, West Altai, Kazakhstan,
    Mongolia, China, Iran and India).
  • These rare males are morphologically different
    from those present in bisexual species or
    populations.
  • This atavism is more frequent in
    parthenogenetic populations from Central Eurasia
    (Iran, Kazakhstan, Ukraine, Mongolia) and less
    frequent, or scarce, in peripheral Western
    (Iberian peninsula, Africa) and Eastern (China)
    populations.

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  • Presence of rare males in diploid parthenogenetic
    Artemia populations from the Old World (2)
  •  
  • Although rare males seem useless in reproductive
    strategies for parthenogenetic females, they are
    not sterile. They can mate and fertilize females
    from the bisexual strains or populations Artemia
    urmiana (lake Urmia, Iran) and Artemia sinica
    (lake Yuncheng, Shanxi, China), producing live
    offspring .
  • It is suspected that this rare male atavism could
    help to explain the origin of parthenogenetic
    strains (monophyletic?, polyphyletic?) from
    lineages leading to present-day Asiatic Artemia
    or from hybridization between two of the Asiatic
    bisexual species (A. urmiana and A. sinica).

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Quantification of rare males found in diploid
parthenogenetic populations of Artemia   N
number of individuals studied from laboratory
populations male/1000 ? ratio of males to 1000
individuals     Origin N male/ Origin
N male/ 1000 1000   SPAIN and
PORTUGAL EURASIA La Mata lagoon
(Alicante) 16,197 2-3 Marg. di Savoia salterns
(Italy) 12,103 1 Janubio salterns
(Lanzarote) 13,092 0 Santa Gilla salterns
(Italy) 4,647 1 Odiel salterns
(Huelva) 14,188 1 Kujalnik lake,
Ukraina 12,656 7-8 Sanlucar salterns
(Cádiz) 12,202 1 Maloje Jar. Lake, W.Altai
8,031 1-2 San Fernando salterns (Cádiz) 12,504
1 Bjurliu lake, Kazakhstan 18,946 9-10 Calpe
salterns (Alicante) 12,000 1 Urmia lake,
Iran 4,689 17 Bonmatí salterns (Alicante)
7,268 2-3 Ka lake, Inner Mongolia 10,931
5-6 Gerri salterns (Lleida) 12,319 1 Dong
Fang Hong salterns, China 8,920 1-2 Aveiro
salterns 18,105 2 Xiao Tan salterns,
China 16,570 5-6 Yingkou salterns,
China 5,920 1-2 AFRICA Madras salterns,
India 3,352 2-3 Walvis Bay,
Namibia 10,066 1 Wadi Natron, Egypt 4,947
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Males
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  • Updating of cyst bank and database (1)
  • The present cyst collection held at the IATS-CSIC
    contains about 280 samples 146 from Western
    Europe, 24 from Asia, 16 from Africa and 94 from
    the Americas.
  • The updating of cyst bank is mainly focused now
    to the study of samples coming from countries
    neighbouring Spain, specially Portugal, France ,
    Italy and North Africa countries.
  •  
  • The biogeography and biodiversity of Artemia
    populations in Spain are well known (Amat et al.,
    1995), and changes about it were not expected,
    unless undue allochthonous species introduction.
  • A similar situation was reported from Portugal
    and France since the early 80s. Narciso (1989)
    and Thiery Robert (1992) rendered preliminary
    information on the presence of A. franciscana
    populations in Portugal and France, respectively.

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  • Updating of cyst bank and database (2)
  • Cyst samples from Portugal, France, Spain and
    Morocco, present in the IATS-CSIC bank, and
    collected between 1991 and 2002, produced A.
    franciscana populations .
  • Preliminary research on Italian cyst samples
    (Tarquinia, Carloforte) are showing, up today,
    autochthonous Artemia populations (A. salina and
    A. parthenogenetica).
  • The suspected absolute presence of A. franciscana
    in Portugal and France is endangering the
    biodiversity of Spanish autochthonous populations
    in the South of Spain (Cadiz and Huelva) at
    short-medium (?) term, and of the Mediterranean
    Spanish autochthonous populations at medium-long
    (?) term.
  • Amat, F., Barata, C., Hontoria, F., Navarro,
    J.C., Varó, I. 1995. Int. J. Salt Lake Res., 3
    175-190.
  • Narciso, L. 1989. EAS Special Publ., 10 183-184.
  • Thiery, A. and Robert, F. 1992. Int. J. Salt
    Lake Res.,1 47-63.
  •  

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Females
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Males
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