Growth parameters and mortality rate of the Scomber japonicus peruanus (Jordán & Hubb, 1925) along the Peruvian coast, South Pacific

The growth parameters and the mortality rates of the Scomber japonicus peruanus (Chub mackerel) were studied based on monthly data of frequency of fork length classes obtained from commercial landings off the Peruvian coast from 1996 to 1998. The asymptotic body length and growth rate values obtained by the ELEFAN I (Electronic Length Frequency Analysis) ranged from 40.20 cm to 42.20 cm and from 0.38 to 0.39, respectively. The oscillation amplitude was 0.60; the Winter point values varied from 0.50 to 0.60 and the performance index from 2.79 to 2.84. The total mortality rate of the Chub mackerel obtained by the linearized catch curve oscillated between 1.68 and 3.35. The rate of fishing mortality varied from 1.16 to 2.78 and the exploitation rate from 0.68 to 0.84. The annual rate of natural mortality estimated by the Pauly's method ranged from 0.52 to 0.53. The results obtained allow us to conclude that the longevity of the Chub mackerel was slightly over seven years.

Pseudohaliotrema paralonchuri sp.n. (Monogenoidea: Dactylogyridae), parasitic on Paralonchurus peruanus (Steindachner) (Teleostei: Sciaenidae) from the peruvian coast

Pseudohaliotrema paralonchuri sp. n., parasitic on the sciaenid fish Paralonchurus peruanus (Steindachner) from the Peruvian central coast, is described, illustrated and compared with related species of the genus. P. paralonchuri differs from other Pseudohaliotrema by the characteristics of the cirrus, accessory piece, anchors and bars. This is the first record of Pseudohaliotrema from the South American Pacific Ocean.

Metazoan Parasite Infracommunities in Five Sciaenids from the Central Peruvian Coast

Parasitological analysis of 237 Menticirrhus ophicephalus, 124 Paralonchurus peruanus, 249 Sciaena deliciosa, 50 Sciaena fasciata and 308 Stellifer minor from Callao (Perú) yielded 37 species of metazoan parasites (14 Monogenea, 11 Copepoda, 4 Nematoda, 3 Acanthocephala, 1 Digenea, 1 Aspidobothrea, 1 Eucestoda, 1 Isopoda and 1 Hirudinea). Only one species, the copepoda Bomolochus peruensis, was common to all five hosts. The majority of the components of the infracommunities analyzed are ectoparasites. The Brillouin index (H) and evenness (J´) were applied to the fully sampled metazoan parasite infracommunities. High values of prevalence and mean abundance of infection are associated to the polyonchoinean monogeneans; the low values of J' reinforce the strong dominance of this group in the studied communities. The paucity of the endoparasite fauna may be a consequence of the unstable environment due to an upwelling system, aperiodically affected by the El Niño Southern Oscillation phenomena.

The Usefulness of Caries Frequency, Depth, and Location in Determining Cariogenicity and Past Subsistence: A Test on Early and Later Agriculturalists From the Peruvian Coast

Dental markers have been used to unravel particularities of paleodiet, subsistence, social structure, and health. This article aims to compare oral pathology among four pre-Columbian groups with different degrees of agricultural and socio-cultural development but comparable ecological conditions who lived on the coastal desert of Peru. Three of these groups are assigned to distinct phases of the Formative Period (2500-1 BC), a time critical for our understanding of the development of agriculture and social complexity. The fourth group corresponds to the Late Intermediate Period (1000-1470 AD), when agriculture had its apogee and society was highly stratified. In this study we test whether there is an increase (1) in the frequency of carious lesions and (2) in caries depth, and (3) if there is a shift from occlusal to extra-occlusal caries locations with the development of agriculture. Therefore, we analyze the frequencies of carious lesions and antemortem tooth loss (AMTL), the caries distributions by age, sex, and type of tooth, as well as the tissues affected by, and the location of the carious lesions. Since there are no significant differences in the frequencies of carious lesions and AMTL between the groups, we reject hypothesis 1. In contrast, caries depth does increase, and caries location changes from occlusal to extra-occlusal sites with agricultural development. However, we can only corroborate hypothesis 2 and 3 when taking into consideration dental wear. Thus, we recommend that caries depth and locations should be used with evaluations of dental wear to reconstruct subsistence in ancient populations. Am J Phys Anthropol 143:75-91, 2010. (C) 2010 Wiley-Liss, Inc.

Growth parameters and mortality rate of the Scomber japonicus peruanus (Jordan & Hubb, 1925) along the Peruvian coast, South Pacific

The growth parameters and the mortality rates of the Scomber japonicus peruanus (Chub mackerel) were studied based on monthly data of frequency of fork length classes obtained from commercial landings off the Peruvian coast from 1996 to 1998. The asymptotic body length and growth rate values obtained by the ELEFAN I (Electronic Length Frequency Analysis) ranged from 40.20 cm to 42.20 cm and from 0.38 to 0.39, respectively. The oscillation amplitude was 0.60; the Winter point values varied from 0.50 to 0.60 and the performance index from 2.79 to 2.84. The total mortality rate of the Chub mackerel obtained by the linearized catch curve oscillated between 1.68 and 3.35. The rate of fishing mortality varied from 1.16 to 2.78 and the exploitation rate from 0.68 to 0.84. The annual rate of natural mortality estimated by the Pauly`s method ranged from 0.52 to 0.53. The results obtained allow us to conclude that the longevity of the Chub mackerel was slightly over seven years.