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1

Cenotes – lakes of the Yucatan Peninsula (Mexico)

100%

Szeroczyńska K. , Zawisza E.

Studia Quaternaria

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2015

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tom Vol. 32, Nr 1

53--57

EN

Cenote lakes are natural sinkholes or depressions resulting from the collapse of limestone bedrock exposing the groundwater underneath. Thousands of such lakes are particularly encountered on the Yucatan Peninsula (Mexico). These lakes were of great significance for the Maya culture as important religious places and primary source of drinking water. They permitted the survival of Mayan communities through dry periods known as “Maya drought”. Most of the cenote lakes are large open water pools measuring tens of meters in diameter. The majority of cenotes are smaller sheltered sites. Their waters are usually very clear and oligotrophic, originating from rain water filtering slowly through the ground. The authors visited and collected zooplankton samples from eight cenotes in November 2013, namely: Ik-Kil, Samula, Zaci, X-Kekn, Actum Ha, Cristal, Sian Ka’an, and Chan Chemuxil (transect Merida–Tulum– Cancun). The analysed lakes differ considerably in morphological terms, varying from very deep to shallow. Some of them are under human impact (tourists). The water samples were analysed for zooplankton content, but the phytoplankton frequently occurring was also taken into account. The obtained results are largely varied, indicated big eco- logical verity among cenotes which depended on lake age, localization and morphometry. As showed our study Cladocera zooplankton was very rare and only present at several sites. Between the fauna community Copepoda and Ostracoda species were the most abundant. Phytoplankton were present in all studied lakes and it sees that played the central role in those ecosystems.

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Czy istnieje sezonowy rytm rozwoju w warunkach tropikalnych? (Raport 1 z dwuletnich comiesięcznych badań na Jukatanie w Meksyku)

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Siniarska A. , Rojas A. , Valentin G. , Wolański N. , Dickinson F.

Studia Ecologiae et Bioethicae

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2004

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tom 2

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nr 1

9-46

EN

The main aim of this work concerns the answer to the question of whether the general regularity of seasonal differences in changes of height, weight, and body components during ontogeny in tropics exists. If so, whether this phenomenon depends on cyclic changes in nature or this rather is an adjustment to local conditions and mode of life. To answer this question the studies took place in the tropical climate of Yucatan and included 49 boys and 47 girls aged 11-12 years and being of Maya, Mestizo, and Creole origin. The youths were attending two schools that were located in rather poor districts of Merida (the capital city of the Yucatan State, Mexico). The investigations started in February 2002 and ended in November 2003 and were continued monthly. The standard anthropometric methodology was applied to measure body height, weight, arm, waist, hip, and calf circumferences, and five subcutaneous fat folds (biceps and triceps brachii, subscapular, suprailiac and calf). Bioimpedance techniques were used to estimate fat mass (FM ), fat-free mass (FFM ), and total body water (TBW). The results show that general regularities in monthly or longer rates of stature increments and increments or declines of body mass do not exist. There are not similar regularities of changes even in groups of coevals of the same gender and within the youths coming from the same district. Each variable shows a quite specific rate of change.

3

Skok pokwitaniowy i budowa ciała dziewcząt z Meridy (Jukatan, Meksyk) jako sposób przystosowania do warunków życia

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Zielińska A.

Studia Ecologiae et Bioethicae

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2003

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tom 1

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nr 1

141-158

EN

The patterns of physical growth (stature, BMI, subscapular and arm fat-fold thickness, upper and lower extremity length, chest circumference, arm, and hip breadth, and age at menarche) were studied in 857 of Maya and Mestizo girls and 1314 of Creole girls aged 6-18 years. Data were collected between 1998-2001 in primary, secondary, and high schools of Merida, Capital City of the Yucatan State, Mexico. The ethnicity of girls was defined using their two surnames (from the father and mother side). The results show that Creoles are taller, have more abundant fat tissue, and greater BMI, especially at the age of 11 years, which means that they are better prepared to start pubertal spurt. Maya girls have relatively longer upper extremities to lower ones, greater biacromial breadth, and chest circumference to stature than Creoles, which shows their more stocky body build. The adolescent (pubertal) spurt in height starts earlier in Creoles (9-10 years) and its rate is greater (max. = 7.48 cm/ year) than in Maya and Mestizos girls (10-11 years; max. = 6.25 cm/year). In Mayas and Mestizos, there is only a slight difference between the rate of changes before and during the pubertal spurt. There are no significant differences in age at menarche between girls from both ethnic groups (11.96 in Mayas and Mestizos and 12.04 in Creoles), but there are statistically significant differences between age at menarche of studied girls and their mothers (12.4 for both groups) in each ethnic group. There is evidence that the onset of pubertal spurt in height and its rate may depend on ethnicity. Creoles may lead to a more “westernized” style of life than the Maya and Mestizos girls.

4

A new species of Malaconothrus Berlese from Yucatan, Mexico [Acari: Oribatida: Malaconothridae]

72%

Palacios-Vargas J. G. , Iglesias R.

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tom 08

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nr 1

5

Sprawność fizyczna dzieci wiejskich i miejskich z niskiej grupy społeczno-ekonomicznej na Jukatanie (Meksyk)

58%

Aftanasiuk M.

Studia Ecologiae et Bioethicae

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2003

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tom 1

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nr 1

127-140

EN

Body build and physical fitness of schoolchildren of low socioeconomic strata from urban and rural areas of Yucatan were studied. The material consisted of 552 children from Merida (the capital city of Yucatan State, Mexico) and of 526 children from the Yaxcaba horticultural community, 7 through 14 years of age. These are cross-sectional samples studied in 1996-97 in Merida and in 1999 and 2000 in Yaxcaba. The ethnic origin was evaluated using two surnames of children (from the father and mother side). The studied variables included stature, BMI, arm circumference, grip strength, agility run, Sargent vertical jump index (explosive strength), spine flexibility index, and reaction time. Urban children are significantly taller than rural ones, and BMI and arm circumference show also a tendency to be greater in urban areas. Physical fitness tests are better performed (better results) in rural areas than in urban ones. If the whole material is divided according to two ethnic groups (Mayas and Mestizos, and Creoles) the differences in body build are still observed but those in physical fitness disappeared. Creole children are taller than Mayas and Mestizos and they show a tendency to have more weight for height and greater arm circumference. Generally, the differences in physical fitness are only observed between rural and urban children what may be caused by a more active way of life in villages than in towns resulting from agricultural activity. However, differences in stature are observed between ethnic as well as between rural and urban groups. This may have the genetic origin (Creoles and Mayas), and in the case of different localities, it may also be caused by more various nutrition in towns than in villages.