An overview of the activities of our team Authors: Rosa Graciela Cohen Alba Graciela Papeschi Ximena Inés Pastorino Francisco Amat

Lagoon in Comandancia Frías (Chaco Prov.): 24º 30´S, 62º 15´W Salinas Grandes (NO Córdoba Prov.): 26º 30´-31º 40´S, 64º 15´-66º 25´W Lagoon 40km Northern Los Juríes (Santiago del Estero Prov.): 28º 03´S, 62º 10´W La Antigua Saline (La Rioja Prov.): 29º 54´S, 66º 07´W Mar Chiquita Lake (Córdoba Prov.): 30º 30´- 31º S, 62º 10´- 63º 10´W Pampa de las Salinas (San Luis-La Rioja Prov.): 32º S, 66º 41’ W Las Tunas Lagoon (Córdoba Prov.): 33º 44´S, 62º 32´W Lagoon in Trenque Lauquen (Buenos Aires Prov.): 35° 48´S, 62° 55´W Lagoon in Área de Naicó (La Pampa Prov.): approximately 36º52´S, 64º 24´W Salinas Grandes de Hidalgo (La Pampa Prov.): 37º 13´S, 63º 26´W Utracán Lagoon (La Pampa Prov.): 37º 17´14´´S, 64º 37´14´´W Guatraché Lagoon (La Pampa Prov.): 37º44´25´´S, 63º 33´15´´W El Carrizal Lagoon (La Pampa Prov.): 37º 50´48´´S, 63º 46´54´´W Colorada Grande Saline or Lagoon (La Pampa Prov.): 38° 18´S, 63° 42´W Colorada Chica Saline or Lagoon (La Pampa Prov.): 38º 23´S, 63º 36´W Callaqueo Saline or Lagoon (La Pampa Prov.): 38º 34´S, 63º 32´W Salitral de la Vidriera (= de Garnica) (Buenos Aires Prov.): 38° 42´S, 62° 40´W Salinas Chicas (Buenos Aires Prov.): 38º 44´S, 62º 57´W Lagoon in San Miguel Field (= of Winchel) (Buenos Aires Prov.): approximately 39ºS, 62º 30´W Palos Blancos Saline or Lagoon (Buenos Aires Prov.): approximately 39ºS, 62º 30´W Lagoon in Hotel Las Termas (Pedro Luro, Buenos Aires Prov.): 39° 30´S, 62°35´W Villalonga Lagoon (=de los Gauchos) (Buenos Aires Prov.): 39° 51´S, 62° 32´W Salitral and Saline of Bajo del Gualicho (Río Negro Prov.): 40º 24´S, 65º 13´W Salina de Luzzetti (Buenos Aires Prov.): approximately 40º 35´S, 62º 40´W Salina del Algarrobo (Buenos Aires Prov.): 40° 36´S, 62° 56´W Salina de Piedras (= Salina de Cagliero) (Buenos Aires Prov.): 40° 41´S, 62° 40´W Saline Pond at the edge of Nat. Route 3, km 1128 (R. Negro Prov.):approximately 40º 43´S, 65º W Salina del Inglés (Buenos Aires Prov.): 40° 43´S, 62° 28´W

MORPHOLOGY BIOMETRY OF CYSTS AND NAUPLII MORFOMETRY OF ADULTS CYTOGENETIC INTER AND INTRAPOPULATIONAL CROSS-BREEDING LIPID PROFILES

Lagoon in Comandancia Frías (Chaco Prov.): 24º 30´S, 62º 15´W Salinas Grandes (NO Córdoba Prov.): 26º 30´-31º 40´S, 64º 15´-66º 25´W Lagoon 40km Northern Los Juríes (Santiago del Estero Prov.): 28º 03´S, 62º 10´W La Antigua Saline (La Rioja Prov.): 29º 54´S, 66º 07´W Mar Chiquita Lake (Córdoba Prov.): 30º 30´- 31º S, 62º 10´- 63º 10´W Pampa de las Salinas (San Luis-La Rioja Prov.): 32º S, 66º 41’ W Las Tunas Lagoon (Córdoba Prov.): 33º 44´S, 62º 32´W Lagoon in Trenque Lauquen (Buenos Aires Prov.): 35° 48´S, 62° 55´W Lagoon in Área de Naicó (La Pampa Prov.): approximately 36º52´S, 64º 24´W Salinas Grandes de Hidalgo (La Pampa Prov.): 37º 13´S, 63º 26´W Utracán Lagoon (La Pampa Prov.): 37º 17´14´´S, 64º 37´14´´W Guatraché Lagoon (La Pampa Prov.): 37º44´25´´S, 63º 33´15´´W El Carrizal Lagoon (La Pampa Prov.): 37º 50´48´´S, 63º 46´54´´W Colorada Grande Saline or Lagoon (La Pampa Prov.): 38° 18´S, 63° 42´W Colorada Chica Saline or Lagoon (La Pampa Prov.): 38º 23´S, 63º 36´W Callaqueo Saline or Lagoon (La Pampa Prov.): 38º 34´S, 63º 32´W Salitral de la Vidriera (= de Garnica) (Buenos Aires Prov.): 38° 42´S, 62° 40´W Salinas Chicas (Buenos Aires Prov.): 38º 44´S, 62º 57´W Lagoon in San Miguel Field (= of Winchel) (Buenos Aires Prov.): approximately 39ºS, 62º 30´W Palos Blancos Saline or Lagoon (Buenos Aires Prov.): approximately 39ºS, 62º 30´W Lagoon in Hotel Las Termas (Pedro Luro, Buenos Aires Prov.): 39° 30´S, 62°35´W Villalonga Lagoon (=de los Gauchos) (Buenos Aires Prov.): 39° 51´S, 62° 32´W Salitral and Saline of Bajo del Gualicho (Río Negro Prov.): 40º 24´S, 65º 13´W Salina de Luzzetti (Buenos Aires Prov.): approximately 40º 35´S, 62º 40´W Salina del Algarrobo (Buenos Aires Prov.): 40° 36´S, 62° 56´W Salina de Piedras (= Salina de Cagliero) (Buenos Aires Prov.): 40° 41´S, 62° 40´W Saline Pond at the edge of Nat. Route 3, km 1128 (R. Negro Prov.):approximately 40º 43´S, 65º W Salina del Inglés (Buenos Aires Prov.): 40° 43´S, 62° 28´W

CHILE Salinas de Cahuil (Pichilemu) 34° 25’ S ARGENTINA Lagoon in Trenque Lauquen (Buenos Aires) 35°48´S

A. franciscana A. persimilis

MORPHOLOGY OF ADULTS  The proportions of the body in both sexes: lengths and widths of thorax and abdomen  The size of the frontal knob in the antenna of the male  The presence or not of a characteristic saddle-like ornamentation on the back of genital segments in the female.  The shape and size of furcal rami and the number of setae they bear, in both sexes.

Population of Las Tunas Lagoon

33° 44’ S latitude Assigned to A. franciscana by MORPHOLOGY OF ADULTS OTHER TECHNIQUES CARRIED OUT: MORPHOMETRY of ADULTS CYTOGENETIC STUDIES BIOMETRY OF CYSTS INTRA AND INTERPOPULATIONAL CROSSES

CYTOGENETIC STUDIES a) Abnormalities in the meiosis chromosomes Heteromorphic bivalents Univalents out of plate at metaphase I Laggards at anaphase I b) Nuclei with an unexpected haploid number: Telophase I poles with different haploid chromosome number Meiotic nuclei with n = 22, n = 23 and n = 21.

BIOMETRY OF CYSTS Mean diameter intermediate among those belonging to several A. franciscana and A. persimilis populations.

Intra Populational Crosses

Inter Populational Crosses

Viability of the Offspring *excluded cysts improperly shelled *excluded dead nauplii + abortive embryos

Viability of the Offspring Expected High viability *excluded cysts improperly shelled *excluded dead nauplii + abortive embryos

Viability of the Offspring Unexpected Low viability *excluded cysts improperly shelled *excluded dead nauplii + abortive embryos

Viability of the Offspring *excluded cysts improperly shelled *excluded dead nauplii + abortive embryos Intermediate Results

Viability of the Offspring *excluded cysts improperly shelled *excluded dead nauplii + abortive embryos Expected Inviability

On the basis of our results we have hypothesized that LT population may be subjected at least to a certain degree of natural hybridization. The geographical proximity of this population with other populations of both A. franciscana and A. persimilis, would allow cysts from both species to converge sporadically in Las Tunas Lagoon, brought by means of winds or waterfowls.

CYTOGENETICS STUDIES Have also been performed in other populations assigned to A. franciscana.  Mar Chiquita Lake  Salinas Grandes (NW Córdoba Prov.)  Pampa de las Salinas  La Antigua Saline

In all these cases, the specific assignation was confirmed, as all the individuals have shown:  regular meiosis and n = 21.  nauplii with 2n = 42  all interphase nuclei from somatic cells with numerous DAPI and CMA bright chromocenters, both in diploid and polyploid cells.

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