Species-level differentiation of two cryptic species pairs of wild cavies, genera Cavia and Galea, with a discussion of the relationship between social systems and phylogeny in the Caviinae.

Canadian Journal of Zoology, 2004, 82 (3): 516-524, 10.1139/z04-010.

Abstract:

Two little-known species of guinea-pig from the genera Cavia and Galea (Cavia magna Ximenez, 1980 and Galea sp. nov.) have recently been studied in more detail with respect to their behavior, social structure, and mating system. To determine the specific distinctness of these little-known species from Cavia aperea Erxleben, 1777 and Galea musteloides Meyen, 1832, crossbreeding between species was tried and it demonstrated that the two Cavia species will rarely cross in captivity to produce hybrids of much reduced fertility, whereas the Galea species could not be crossed. To analyze the phylogenetic position of C. magna and Galea sp. nov., we present an analysis based on major parts of the 12S (778 base pair) and 16S genes of mitochondrial RNA (1435 base pair) in conjunction with corresponding data on all other genera of the Caviinae. We also determined the relationship between C. magna and the sympatric wild guinea-pig (C. aperea) and its domestic form (Cavia aperea f. porcellus (Linnaeus, 1758)). Phylogenetic and distance analysis of all genera of cavies (Cavia (two species), Galea (two species), Kerodon, Microcavia) showed the close relationship of C. magna with C. aperea and the latter's particularly low genetic distance to C. aperea f. porcellus. Galea sp. nov. differed markedly from G. musteloides. Of the three genera, Galea appears most distinct. The genus Kerodon clustered with the genus Hydrochaeris, supporting the previous conclusion by Rowe and Honeycutt (2002. Mol. Biol. Evol. 19: 263-277) regarding the placement of the genus Hydrochaeris within the Caviidae. Recently published data on the social systems of the above-mentioned cavy species, however, show their great inter- and intraspecific social flexibility and contradict the interpretation of the same authors about a simple relationship between phylogeny and social systems in the Caviidae.

 

trillmich-biblio

Freigegeben in T
Donnerstag, 14 Juni 2018 23:40

KRAUS C., TRILLMICH F. & KUNKELE J. (2005)

Reproduction and growth in a precocial small mammal, Cavia magna.

JOURNAL OF MAMMALOGY 86 (4): 763 - 772.
DOI: 10.1644/1545-1542(2005)086[0763:RAGIAP]2.0.CO;2

Abstract:

Small mammals usually produce large litters of altricial young, resulting in high reproductive rates. In contrast, cavies give birth to few precocial young after a long gestation. The price of this reproductive strategy is a low intrinsic rate of natural increase. We investigated if the patterns of reproduction in a wild population of Cavia magna are consistent with the hypotheses that cavies can increase their reproductive output by breeding aseasonally and by maturing extremely early. We collected data on reproduction and growth by capture-recapture during a 26-month field study in a wetland in Uruguay, and from a laboratory population founded with individuals from the same region. Among the Caviinae, C. magna is particularly precocial, with individual neonates weighing on average 18% of maternal mass. Reproduction was mostly seasonal, with the main birth season starting at the end of September (austral spring) and extending until May in 1999 and February in 2000, respectively, with only a few females reproducing during the 1st but not the 2nd austral winter. Individual females produced on average 3 litters per year. Some females born in early spring conceived successfully between the age of 30 and 45 days, similar to females in the laboratory. The remainder of the 1st spring cohort and females of subsequent birth cohorts delayed reproduction until the following spring. Body condition and growth rates were highest in the spring, declined through the year, and varied between years, and may be the proximate factors deten-nining whether an adult female or a juvenile initiates breeding. Breeding opportunistically whenever conditions allow might partly compensate for the low reproductive rate of cavies.

 

kraus-biblio

Freigegeben in K
Donnerstag, 14 Juni 2018 18:50

JORDAN, B. (2006)

Eine neue Meerschweinchenart: Das Sumpfmeerschweinchen (Cavia magna) in Menschenhand.

RODENTIA 31, Mai/Juni 2006, S.20

 

jordan-biblio

Freigegeben in J
© Peter Dollinger, Zoo Office Bern hyperworx