[MARMAM] New publication

Gallo, Juan Pablo Gallo jpgallo at ciad.mx
Wed Sep 10 13:56:26 PDT 2014


Dear colleagues,

We are pleased to announce our new publication:
*Gallo-Reynoso J.P., E. O. Francisco and Ch. L. Ortiz. 2014. Age
estimation on long-beaked common dolphins, Delphinus capensis, from
the Gulf of California. Estimación de la edad en el delfín común de
rostro largo, Delphinus capensis, del **Golfo de California. *
THERYA, august, 2014 Vol.5(2): 449-460. DOI: 10.12933/therya-14-198

*Abstract:*

*Introduction: *We estimated the age of 41 long-beaked common
dolphins, Delphinus capensis, found stranded in Sonora and Baja
California beaches in the Gulf of California from 1981 to 2000. The
aim of our work was to know the age and if possible the size of
stranded dolphins and the possible causes of their
stranding.*Methods:* Dentinal growth layers in teeth were revealed
using an acid-etching technique; it involves preparation of
half-etched teeth by grinding and polishing with sandpaper (220-600
grit) and demineralization in 5% formic acid. A stereo-microscope was
used for counting annual growth layer groups (GLGs). Four different
readers of dentinal layers assisted to obtain the estimate of
age.*Results:* Age category estimates were: 17 individuals were adults
(12-21 GLGs), 10 individuals were subadults (7-12 GLGs), 10
individuals were juveniles (2-7 GLGs), and 4 individuals were nursing
calves (<1 GLG). 15 individuals were measured and sexed on the field
(6 calves, 6 subadults and 3 adults). Larger dolphins were the older
ones: the longest male of 264.7 cm presented 21 GLGs, and the longest
female of 252.4 cm was 18 GLGs (one GLG corresponding to one year).
Independent of the sex of the dolphins, the regression of age on
length was significant with an r2 = 0.7068, P < 0.0001.*Discussion:*
Age estimates can serve to know the vulnerability and incidence of
long-beaked common dolphins of different ages due to toxic algae
effects (Domoic acid) or to the biomagnification of man-made toxins
used for agriculture, due to the ingestion of small pelagic fishes
that accumulates these toxins. It also can provide insight in fishery
interactions and mortality on D. capensis in the Gulf of California.
With regards

Dr. Juan Pablo Gallo Reynoso
Profesor-Investigador
Centro de Investigación en Alimentación y Desarrollo A.C., Unidad Guaymas
Carretera a Varadero Nacional km 6.6
Col. Las Playitas, Guaymas, Sonora
C.P. 85480, México
Teléfono: +52 (622) 225 28 24
http://www.ciad.mx/guaymas/nutrias/INDEX.HTM
https://www.researchgate.net/profile/JP_Gallo-Reynoso/?ev=hdr_xprf
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