Subsistencia y movilidad de los cazadores-recolectores que ocuparon Cueva TrafulI durante el Holoceno Medio y Tardío.

Se presentan los resultados del análisis del conjunto óseo del Holoceno Medio y tardío de cueva TrafulI (provincia del Neuquén, Argentina). A partir de ellos discutiremos aspectos como la subsistencia y la movilidad de las sociedades cazadoras-recolectoras y la estacionalidad de sus ocupaciones. Las sociedades cazadoras-recolectoras que ocuparon este espacio explotaron recurrentemente al guanaco como parte de sus prácticas de subsistencia. Esta forma de vida se generalizó a mediados del Holoceno, en el ecotono y la estepa, pero siempre se complementó con fauna menor, moluscos, peces o vegetales. En el tránsito de los últimos 2.000 años la cantidad de especies explotadas aumentó significativamente junto con la diversidad. Este fenómeno se debió a la reducción de los rangos de acción mayormente impulsada por la circunscripción territorial de los grupos, que comenzaron a diferenciarse interétnicamente. La incorporación de la tecnología cerámica permitió: diferir el consumo de algunos recursos, extraer más eficientemente la grasa de los huesos y procesar vegetales. Estas condiciones materiales de existencia son interrumpidas por la conquista española. Posteriormente a ésta, la adopción del caballo cambió radicalmente el modo de vida de los cazadores-recolectores pedestres.publishedVersio

The Giant Mottled Eel, <i>Anguilla marmorata</i>, Uses Blue-Shifted Rod Photoreceptors during Upstream Migration

<div><p>Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. <i>Anguilla marmorata</i>, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of <i>A. marmorata</i> during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λ_max of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2) revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292) and four putative (S124, V189, V286, I290) tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.</p></div

The mean λ_max of rod cells from <i>A. japonica</i> and <i>A. bicolor pacific</i> glass eels, as determined using MSP.

<p>All values are expressed in nanometers (nm) ± SD. The number of photoreceptor cells measured is indicated in parentheses.</p><p>N and n indicate the number of specimens and cells examined, respectively.</p

The mean λ_max of photoreceptor cells from <i>A. marmorata</i> at different developmental stages, as measured using MSP.

<p>All values are expressed in nanometers (nm) ± SD. The number of photoreceptor cells measured is indicated in parentheses. N and n indicate the number of specimens and cells examined, respectively.</p

Comparisons of the spectral sensitivities of rod and cone cells at different developmental stages of <i>A. marmorata</i> by <i>t</i>-test.

<p>The upper-right half presents the <i>t</i>-test results for rod cells, while the lower left half presents those for cone cells.* indicates P<0.05; NS, no significant difference: P>0.05.</p

Comparisons of the Rh2 and SWS2 sequences of freshwater eels.

<p>* indicates the opsin gene obtained in this study.</p><p>Sequences are compared to the consensus sequence, with identical amino acids indicated by a dot. Sites are numbered according to bovine rhodopsin.</p

The relative expression (A) and proportional expression (B) of opsin genes at different developmental stages of <i>A. marmorata</i>, as determined by quantitative RT-PCR of retinal RNA.

<p>The relative expression (A) and proportional expression (B) of opsin genes at different developmental stages of <i>A. marmorata</i>, as determined by quantitative RT-PCR of retinal RNA.</p

Distribution histograms of the λ_max of photoreceptor cells at four stages of <i>A. marmorata</i>.

<p>(A) Glass eel; (B) Cultured yellow eel; (C) Wild yellow eel. Rod cells: black bars. Cone cells: white bars.</p

Neighbor joining trees of the freshwater eel Rh1 (A), Rh2 (B), and SWS2 (C) opsin and (D) <i>cytochrome b</i> genes based on Maxima-likelihood distances.

<p>The scale bar represents 0.05 nucleotide substitutions. The nucleotide sequences of fish opsin genes were obtained from GenBank. The genes and their accession numbers are listed in Table S3. ^a λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone-0103953-t001" target="_blank">Table 1</a> & <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone-0103953-t006" target="_blank">Table 6</a>. ^b λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone.0103953-Wood2" target="_blank">[15]</a>. ^c λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone.0103953-Beatty1" target="_blank">[12]</a>. ^d λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone.0103953-Shapley1" target="_blank">[71]</a>. ^e λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone.0103953-Wang3" target="_blank">[65]</a>.</p

Experimental treatments.

<p>11 KA: 11-ketoandrostenedione implants; Empty: empty implants; GSI: gonadal somatic index in females; KSI: kidney somatic index in males. Short day (L8D16) and long day (L16D8) photoperiod.</p