306 V. Sabatinietal. m tus branchs, approximately 1.5 in length stretched perpendicular to the body; and, and 5.0cm in diameter, were provided to with the sternum on the floor and the each pen, and exchanged for new ones limbs close to the body (i.e.: the sternal after 15 days. The hay that remained out- Position). Caecotrophy occurred when the side the burrows was swept out ofthe pens animals were resting in the sternal Posi- every morning. Every ten days, the whole tion, by raising the ehest off the ground, pen floor was washed, even inside the bur- then putting the snout between the hind rows after the hay had been removed, and legs andrepeatedly lickingthe anus; andfi- the water tanks were brushed. All mainte- nally lifting the head and chewing for nance ofthe animals was performed by the about ten seconds, swallowing soon after. same two staff persons, who had already This cycle was repeated up to ten times. been doing this work for at least one year All adults and immature pacas over two before the study started. months old showed this behaviour daily, Observationswere registered by continuous throughout the diurnal Observation period, recording (Martin and Bateson 1986), with however, one adult female performed cae- all registry done in a descriptive manner by cotrophy during nocturnal observations. the same observer. Observations began in Consumption offaeces by captive pacas has February 1998, and were conducted from previously been reported (Matamoros 7.30h a.m. to 3.00h p.m. (daylight) for 40 1982), but no mention was made of caeco- consecutive days, for a total of 148hours. trophy ofdifferentiated faeces. Nocturnal observations were made from Since pacas have large intestines with a March to July of the same year, from functional caecum (Bentti 1981) and since 5.30hp.m. to 10.00hp.m., over scattered they are phylogenetically related to hystri- days for a total of31 hours. The night sche- cognaths who perform caecotrophy, the dule was selected, based on a previous consumption of differentiated faces should study for 72 hours of continuous Observa- be interpreted as related to the feeding ha- tion of the activity rhythm. These pacas bits ofpacas and not as an abnormal behav- showed an activity peak from 5.30hp.m. iour resulting from captivity (Grier 1984). to 10.00hp.m. In addition, the animals Although studies concerning the natural were observed for two more days, between feeding habits of this species are lacking, 6.00hp.m. to 12.00h a.m. and 12.00h a.m. pacas have been considered to be frugi- to 6.00h a.m. In order to acclimate the ani- vores. The occurrence of caecotrophy and mals to artificial light, two nights before their digestive tract anatomy suggests that each nocturnal Observation two lamps (with pacas may be more herbivorous than ex- 40watt each, positioned 5 m equidistant) il- pected, often browsing on leaves, and not luminated the four pens. Observations in- only when fruits are scarce. side the burrows were possible since one corner of the wood cover was lifted 30cm with a wire. Acknowledgements Although defecation occurred mainly at night, caecotrophy was detected only once We are greatful to Dr.Mauricio Barbanti during the nocturnal observations, and this Duarte for access to the pacas of the Wild Ani- caecotrophy was of already defecated mal Section, atthe Universidade EstadualPaulis- faeces. Ingestion of faeces directly from ta-Jaboticabal, and to Dr. Carlos Ruiz-Miranda the anus was, in contrast, only observed for devoted readings, English revisions and sug- during daytime, always occurring inside gestions for the final manuscript. We also thank the anonymous reviewers for their helpful com- the burrows. The paca can rest in the bur- ments on the previous version ofthis manuscript. row using three different positions: with Financial support was supplied by the Conselho the belly upward and the four limbs flexed Nacionalde DesenvolvimentoCientificoeTecno- near the body; with the bodyside and lögico-CNPq,aBrasiliangovernmentalinstitution cheek on the floor and the four limbs forscientificandtechnological development. Caecotrophyin pacas 307 References Morot,M. Ch. (1882): Des pelotes stomachales des leporides. Mem Soc. Centr. Med. Vet. 12, Ayres,J.M; Lima,D.M.; Martins,E.S.; Bar- 139-239. reiros,J.L.K. (1991): On the track of the Osawa,R.;Blanshard,W.H.;Ocallaghan,P. 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(1991): Hunting yields and game Times Mirror/Mosby College Puhl, Missouri: composition over ten years in a Amazon in- D. Bowen. dian territory. In: Neotropical Wildlife Use Harcourt,A.H.; Stewart,K.J. (1978): Copro- and Conservation. Ed. ByJ. G.Robinsonand phagybywildmountaingorillas. E. Af. Wildl. K.H.Redford. Chicago: Univ. Press. Pp. 53- J. 16,223-225. 81. Marounek,M.; Vovk,S.J.: Skrivanova.V. (1995): Woods,C.A. (1984):Hystricognathrodents.In:Or- Distributionofactivityofhydrolytic enzymes ders and Families of Recent Mammals of the inthedigestivetractofrabbits.BritishJ.Nutr. World. Ed. ByS.Anderson andJ.K.JonesJr. 73,463^69. Canada:JohnWiley.Pp.389-445. Martin,P; Bateson,P. (1986): Measuring Beha- viour - an introductory guide. Cambridge: Authors' addresses: CambridgeUniv.Press. Vera Sabatini, Laboratörio de Ciencias Ambien- Matamoros,Y. (1982):Notassobrelabiologiadel tais/CBB,UniversidadeEstadualdoNorteFlumi- tepezcuinte, Cuniculuspaca, Brisson (Roden- nense/RJ. Av. Alberto Lamego, 2.000 Campos tia: Dasyproctidae) en cautiverio. Brenezia 28015-620, RJ, Brazil, and M.J.R.Paranhos- 19/20, 1-82. DaCosta. Departamento de Zootecnia, Univer- Mondolfi,E. (1972): Lalapao paca. Def. Nat. 2, sidade Estadual Paulista, Jaboticabal. 14884-900, 4-16. SP, Brazil. Mamm. bioi. 66 (2001) 308-311 |Ä| Mammalian Biology © Urban & FischerVerlag C^5SP http://www.urbanfischer.de/journals/mammbiol ^HP* Zeitschriftfür Säugetierkunde Short communication Protein polymorphism in two species of Ctenomys (Rodentia, Ctenomyidae) from Cördoba province, Argentina By A. Bortoluzzi, Mercedes Gutierrez, J. Baldo, and Cristina N. Gardenal Museo de Zoologia, Facultad de Ciencias Exactas, Fisicasy Naturales and Cätedra de Qmmica Biolögica, Facultad deCiencias Medicas, Um'versidad NacionaldeCördoba, Cördoba, Argentina ReceiptofMs. 09. 10. 2000 Acceptance ofMs. 03. 05. 2001 Key words: Ctenomys bergi, Ctenomys rosendopascuali, allozymic polymorphism, speciation Fossorial rodents of the genus Ctenomys karyotypic forms of Ctenomys (Bidau et al. are widespread in southern South America, 1996; Mascheretti et al. 2000). The aim of from 17° to54° S (Cabrera 1961; Reig et al. this study is to analyze the allozymic poly- 1990). The genus comprises 60 recognized morphism in two populations of Ctenomys species originated by an explosive specia- from the north of Cördoba, Argentina as- tion process, promoted mainly by chromo- signed to C bergi and C. rosendopascuali, somal rearrangements (Bidau et al. 1996). inorderto determine theirlevelofdifferen- At present, systematic relationships among tiation at structural loci. species of Ctenomys are poorly known and/ Fourteen specimens of C bergi from Las or controversial. Toscas (30°ir S, 64°54' W, near an extense Thomas (1902) cited the species C bergi for salt mine called Sahnas Grandes) and 16 in- NW the of Cördoba province, Argentina, dividuals of C. rosendopascualis obtained in being Cruz del Eje the type locality. On the proximity of the mouth ofXanaes river the basis of geographic criteria, all the po- (Mar Chiquita saline lagoon, 30°55' S pulations from the north of that province 62°44'W) were used in this study. were included in that species (Bidau et al. Animals were killed by ether anesthesia, li- 1996). ver and kidneys removed immediately and Chromosomal studies revealed that indivi- preserved at -30°C until used. Homoge- duals from the NE of Cördoba have a di- nates, vertical starch gel electrophoresis and ploid number 2n = 52 (FN = 66) but those staining procedures were carried out as de- NW proceeding from the (Salmas Grandes) scribed by Gardenal et al. (1980) and Gar- presented a karyotype of2n = 48 (FN = 90) denal and Blanco (1985). The following (Reig et al. 1990). This last form was as- enzymes were analyzed (loci scored and signed to C. bergi and the former was de- E.C. numbers in parenthesis): liver and kid- scribed as a new species and denominated ney acid Phosphatase (AcpL-l, AcpL-2, C. rosendopascuali (Contreras 1995). AcpK-3, AcpK-4; 3.1.3.2), aspartate amino- Several authors have emphasized the im- transferase (Aat-1, Aat-2; 2.6.1.1), liver so- portance of the application of biochemical luble esterases (Es-1L to Es-6L 3.1.1.1), cat- ; and molecular methods in order to confirm alase (Cat; 1.11.1.6), phosphoglucomutase and clarify the taxonomic Status ofdifferent (Pgm-1, Pgm-2; 2.7.5.1), leucine aminopepti- 1616-5047/01/66/05-308$15.00/0. Protein polymorphism in Ctenomys 309 dase (Lap-1, Lap-2; 3.4.11.1), malic enzyme mammals with low vagility and socially- (Me; 1.1.1.40), lactate dehydrogenase (Ldh; struetured mating System (Nevo et al. 1.1.1.27), alcohol dehydrogenase (Adh; 1990). Values of heterozygosity obtained in 1.1.1.1), glycerophosphate dehydrogenase this study are higherthanthe meanreferred (Gpdh; 1.1.1.8), malate dehydrogenase for fossorial rodents (H= 0.0311) and for (Mdh-l,Mdh-2; 1.1.1.37), isocitrate dehydro- genase (Idh-1, Idh-2; 1.1.1.42), 6-phospho- gluconate dehydrogenase (6-Pgdh; 1.1.1.43) Table 1. Allelefrequencies, proportion ofPolymorphie and glucose-6-phosphate dehydrogenase Loci (95% and 99% criteria) and observed and ex- (G-6-pdh; 1.1.1.49). pected heterozygocityin Ctenomysbergiand Ctenomys The allele coding for the band migrating rosendopascualifrom Cördoba province (Argentina). fastest to the anode was assigned the num- ber 100; thatControlling the fastest cathodic Locus Allele C. bergi C. rosendopascuali band, -100. The other alleles were num- Lap-2 100 1.000 0.929 bered according to their relative mobility 88 0.000 0.071 from the origin. Bands with the same mobi- AcpK-l 100 0.067 0.036 lity were considered homologous. 90 0.900 0.857 Proportion of Polymorphie loci (95% and 81 0.033 0.107 99% criteria), mean observed and expected Adh -100 0.867 0.864 -50 0.133 0.136 heterozygosities, Rogers1 genetic distance Gpdh 100 1.000 0.923 (1972) and Nei's identity (1975) among po- 60 0.000 0.077 pulations were calculated using the program Acp -3 100 0.094 0.038 L Biosys-1 (Swofford and Selander 1989). 78 0.906 0.962 Sixteen out of 27 loci analyzed were Poly- AcpL-4 100 0.031 0.000 morphie at least in one population. Table 1 71 0.969 1.000 shows allele frequencies, proportion of Aat-1 100 0.000 0.0154 Polymorphie loci (P), and observed and ex- 72 0.969 0.0846 pecteHd mean heterozygosity per locus (HQ Es-1 10200 00..083414 00..085050 and e) for the two populations analyzed. 93 0.156 0.115 Locus G-6-pdh was the only one presenting Es-2 100 0.563 0.731 a different allele fixed in each population. 94 0.438 0.269 Although crossing tests were not per- Es-3 100 0.906 0.885 formed, the genetic control of the electro- 88 0.094 0.115 phoretic patterns observed was postulated Es-4 100 0.000 0.077 on the basis of similar polymorphisms de- 89 0.656 0.615 scribed for other rodent species where the 85 0.344 0.308 Mendelian transmission of variants has Es-5 100 0.000 0.038 89 1.000 0.962 been demonstrated (Gardenal and Blan- Es-6 100 0.813 0.269 co 1985; Gardenal et al. 1980; Garci'a and 77 0.188 0.731 Gardenal 1989). In all cases, the observed Pgm-2 100 1.000 0.846 genotypic frequencies did not differ signifi- 82 0.000 0.154 cantly from the expected ones according to Me 100 0.063 0.000 the Hardy-Weinberg equilibrium. 89 0.938 1.000 Rogers1 genetic distance and similarity be- G6pdh 100 1.000 0.000 tween the two species was 0.094 and Nei's 87 0.000 1.000 distance and identity were 0.059 and 0.942, P (95%) 33.33 40.74 respectively. P(99%) 40.75 48.15 Levels of polymorphism revealed in this Ho (%) 10.1 12.8 study for C. bergi and C. rosendopascuali (s.e. 3) (s.e. 3.4) are particularly high when compared with HE (%) 9.3 11.7 those reported for other subterranean (s.e. 2.8) (s.e. 2.9)