Influence of physicochemical variables in the size structure and distribution of Meoma ventricosa grandis (Echinodermata: Brissidae) within the Boca Chica Channel, Acapulco, Mexico
Por:
Torres-Martinez, Miguel A., Solis-Marin, Francisco A., Laguarda-Figueras, Alfredo, Sour-Tovar, Francisco
Publicada:
1 ago 2016
Resumen:
In this study we examine different physicochemical variables (sediment
texture, temperature, salinity, dissolved oxygen, turbidity, nitrite,
nitrate, ammonium, phosphate, organic matter of marine snow, organic
matter of sediment and organic matter of digestive tract) and their
influence on the size structure and distribution of Meoma ventricosa
grandis. The study was conducted in 3 workstations (E1: La Playa, E2: El
Jardin, E3: Palmitas) located across the Boca Chica Channel, Acapulco,
Mexico, during 2006 to 2007. The results of the measurements of the body
size showed a higher percentage of adults in workstation 1 and 2 (13 and
5%, respectively); however, in workstation 3 the percentage was of
51%. The variance pointed a significance in the size of the individuals
from the workstation Palmitas, showing the largest specimens throughout
the study. The sediment texture in workstations La Playa and El Jardin
was characterized by asymmetric clasts of coarse sand and gravel of
different sizes, with a sediment layer with a depth of layer of 20-30
cm. Unlike workstation of Palmitas wich was distinguished by almost
symmetrical gravel clasts, similar in size and with depth of 50 cm; in
all workstations juveniles were buried between 10 and 20 cm and adults
between 15 and 40 cm of depth. The gonadal index was asynchronous,
presenting the highest reproductive peaks in Palmitas. Regression Trees
analysis established that the organic matter deposited in the sediment
acts as the primary physicochemical variable in the distribution of the
echinoid within the channel, locating until 6,571 individuals in direct
relation to it. The largest number of specimens (11,330) was obtained in
the presence of organic matter, nitrates and phosphates. This is the
first time that genus Meoma is related to a specific substrate according
to the body size.
Filiaciones:
Torres-Martinez, Miguel A.:
Univ Nacl Autonoma Mexico, Dept Paleontol, Inst Geol, Ciudad Univ, Mexico City 04510, DF, Mexico
Solis-Marin, Francisco A.:
Univ Nacl Autonoma Mexico, Lab Sistemat & Ecol Equinodermos, Inst Ciencias Mar & Limnol, Apdo Post 70-305, Mexico City 04510, DF, Mexico
Laguarda-Figueras, Alfredo:
Univ Nacl Autonoma Mexico, Lab Sistemat & Ecol Equinodermos, Inst Ciencias Mar & Limnol, Apdo Post 70-305, Mexico City 04510, DF, Mexico
Sour-Tovar, Francisco:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Biol Evolut, Museo Paleontol, Ciudad Univ, Mexico City 04510, DF, Mexico
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