Do Male Kinosternon Scorpioides (Linnaeus, 1766)
Total Page:16
File Type:pdf, Size:1020Kb
186 SHORT NOTE HERPETOZOA 26 (3/4) Wien, 30. Jänner 2014 SHORT NOTE Do male Kinosternon scorpioides characteristics to female body size and envi - (LiNNAEuS , 1766) select and ronmental variables; reproductive period; monopolize females? nesting behavior and ecology (P RiTCHARD & T REBBAu 1984; mENDONçA et al. 1987; The mating systems in vertebrates can CLARK et al. 2001; RuEDA -A L mONACiDi et be monogamous or polygamous (polygy - al. 2007; DODD 2008; LiNDE mAN 2008; nous, polyandrous and polygynandrous) vOgT 2008; mACiP -R íOS et al. 2009; BERRy (EmLEN & O RiNg 1977; SRiPRATEEP et al. & i vERSON 2011; ivERSON & v OgT 2011; 2013). According to these authors, polygy - CHAvES et al. 2012; i vERSON et al. 2012). nous systems, in which one or a few males informa tion regarding mating systems in mate with several females, may have domi - this group was not found. nant males that form harems and prevent The Scorpion mud Turtle Kinosternon other males to mate with females belonging scorpioides LiNNAEuS , 1766 (Kinosterni dae), to the harem. Thus, few males, usually the is found in the freshwaters of north, northeast larger ones, are able to reproduce, while and center-west of Brazil ( RuEDA -A LmO- many others (mostly the smal ler ones) have NACiDi et al. 2007; vOgT 2008; COSTA et al. less chance of leaving descendants. 2010). Regarding sexual dimorphism, there The formation of these harems is usu - is evidence of larger males ( BERRy & S HiNE ally associated with the presence of sexual 1980) and larger females ( CASTRO 2006). dimorphism. According to SHiNE (1978), There are no records of fighting between intrasexual competition for reproductive males for females and harems formation in females produce males larger than females this species. This study aims to report and in some species of snakes. This pattern is discuss the presence of a polygynic mating also known and studied in lizards ( COx et al. system in the aquatic species K. scorpioides 2003). Acco rding to BERRy & S HiNE (1980), and the lack of preference of males of this males are larger than females in semiaquat - species in relation to the size of females. ic and bottom walking aquatic turtles where Seven adults of Kinosternon scorpi - there is fighting or males subdue the oides (three males and four females) were females during copulation (forced insemi - maintained for one year (February 2012 to nation). Formation of harems and territori - January 2013) in a cement tank size (2.7 m ality are common in vertebrates ( ANiBALDi x 2.1 m x 0.3 m) on the outside of the et al. 1998; ORTEgA & A RiTA 1999; m AHER Núcleo Regional de Ofiologia da universi - & L OTT 2000; C uADRADO 2001; K LOSE et al. dade Federal do Ceará (NuROF-uFC). The 2009). in turtles, fighting for females and animals were recogni zed by their size, col - establishment of dominant males mostly oration as well as anomalies present. They occur in terrestrial species (H ARLESS 1979; were fed two or three times a week with BERRy & S HiNE 1980; N iBLiCK et al. 1994; neonatal mice, beef and poultry and dog’s KESWiCK et al. 2006; mANN et al. 2006). food. From monday to Friday, behavioral Polyandry is common in sea turtles observations of the ‘scan’ sampling type (P EARSE & A viSE 2001; CRimm et al. 2002; (mARTiN & B ATESON 2009) were made mOORE & B ALL 2002; L EE & H AyS 2004; every two hours, from 08:00 h to 18:00 h. BOWEN & K ARL 2007) and freshwater tur - Despite the nocturnal activity of K. scorpi - tles (v ALENZuELA 2000; P EARSE et al. 2002; oides , nocturnal samplings were not per - FANTiN et al. 2008); it increases hatching formed, hence it was not possible to pre - success and genetic diversity among the off - clude copulations at night. in addition occa - spring ( PEARSE & A viSE 2001; PEARSE et al. sional observations were made since the 2002). However, polygyny is less common tank was located in a well visible and acces - in aquatic turtles ( CRimm et al. 2002). Accord - sible place. A total of 418 scans were per - ing to these authors, recording of this mat - formed. Chi-square analysis was used to ing system was related to a female-biased assess whether the dominant male showed sex ratio present in the study area. preference for a particular female. The The present knowledge of Kinoster - analysis was developed in the free statistical nidae reproduction is focused in egg size software R ver. 2.13.0 (http://www.r-proj - and clutch size and the relation of these ect.org/) at a significance level of p = 0.05. SHORT NOTE HERPETOZOA 26 (3/4) Wien, 30. Jänner 2014 SHORT NOTE 187 The authors recorded 21 events of male subdues the female in order to copulate. copulation, all performed by the largest This type of reproduction occurs in K. scor - male with multiple females present in the pioides (BERRy & S HiNE 1980; C ASTRO tank. The two smaller males were never 2006), a fact also observed in this study. seen copulating and no agonistic interac - Based on this hypothesis, we predict that tions were observed between males. The smaller females should copulate more fre - dominant individual showed no pre ference quently than larger ones, since they would be for certain females ( χ2 = 0.67, P = 0.881). less resistant to subjugation. However, the Fighting for females and the formation lack of prevalence of copulations with small - of “harems” is chiefly reported from terres - er females observed in this study refutes this trial turtle species (references given above). hypothesis. This result also reinforces the Thus, the record of the occurrence of this need and importance of more studies, prefer - mating system in an aquatic species is note - ably in natural habitats, of mating systems in worthy. However, care is needed interpreting order to better understand sexual dimorphism results from studies in captivity because the in turtles. The existence of a polygynic mat - conditions under which the animals are held ing system forming “harems” is a novelty in may be different from those found in nature. kinosternids, which should be subject to EmLEN & O RiNg (1977) state that the studies in the natural environment. monopoly of resources, such as reproductive REFERENCES: ANiBALDi , C. & L uiSELLi , L. & females, directly depends on the balance be - ANgELiCi , F. m. (1998): Notes on the ecology of a sub - tween the advantages of the monopoly urban population of Rainbow lizards in coastal Kenya.- (increased fitness) and the disadvantages African Journal of Ecology, malden; 36: 199-206. BERRy , J. F. & ivERSON , J. B. (2011): Kinosternon scor - existing (damage by fighting and energy pioides (LiNNAEuS , 1766) – Scorpion mud Turtle; pp. invested in disputes). These authors empha - 63.1-63.15. in: RHODiN , A. g. F. & PRiTCHARD , P. C. H. size that harems usually occur when females & vAN DiJK , P. P. & SAumuRE , R. A. & BuHLmAN , K. A. &ivERSON , J. B. & miTTERmEiER , R. A. (Eds.): Con - have an aggregated distribution for second - servation biology of freshwater turtles and tortoises: A ary reasons, not breeding, and males utilize compilation project of the iuCN/SSC Tortoise and this aggregation to exercise the monopoly. in Freshwater Turtle Specialist group.- Chelonian Re - the case discussed in this study, the small search monographs No 5, Lunenburg. BERRy , J. F. & SHiNE , R. (1980): Sexual size dimorphism and sexual area of the tank in which the animals were selection in turtles (Order Testudines).- Oecologia, New accommodated may have increased the york; 44 (2): 185-191. BOWEN , B. W. & KARL , S. A. aggregation of females and thus facilitated (2007): Population genetics and phylogeography of sea the monopoly of the larger male. in the wild, turtles.- molecular Ecology, malden; 16: 4886-4907. CASTRO , A. B. (2006): Biologia reprodutiva e cresci - this species can move considerable distances mento do muçuã Kinosternon scorpioides (LiN NAEuS , on land in search of vacant water bodies 1766) em cativeiro. msc Thesis, universidade Federal (P RiTCHARD & T REBBAu 1984 ). in doing so, do Pará, Belém, Brazil, pp. 100. CHAvES , E. P. & potential competitors/rivals would avoid OLivEiRA , S. C. R. & A RAúJO , L. P. F. & O LivEiRA , A. S. & m igLiNO , m. A. & A BREu -S iLvA , A. L. & m ELO , F. A. male-male encounters; this might relativize & S OuSA , A. L. (2012): morphological aspects of the the importance of strategies towards female ovaries of turtle Kinosternon scorpioides raised in cap - monopolization. in many turtle species, tivity.- Pesquisa veterinária Brasileira, Rio de Janeiro; 32 (7): 667-671. CLARK , P. J. & E WERT , m. A. & N ELSON females have the potential of sperm storage, C. E. (2001): Physical apertures as constraints on egg which allows them to increase its fitness by size and shape in the Common musk Turtle, Sterno - chosing the male’s sperm used and by saving therus odoratus .- Functional Ecology, malden; 15: 70- energy avoiding additional copulations 77. COSTA , H. D. & m O LiNA , F. DE B. & S ãO -P EDRO , v. DE . A. & F EiO , R. N. (2010): Reptilia, Testudi nes, Kino - (P EARSE & A viSE 2001). The monopoly of a sternidae, Kino sternon scorpioides (LiNNAE uS , 1766): larger male would also reduce costs with Distribution extension.- Check List, Campi nas; 6: 314- additional matings and guarantee a good fit - 315. COx , R. m. & S KELLy , S. E. & J OHN -A LDER , H. B . ness to females’ offspring, despite the gene - (2003): A comparative test of adaptive hypotheses for sexual size dimorphism in lizards.- Evolution, malden; tic variability is reduced. 57 (7): 1653-1669. CRimm , J. L. & S POTiLA , L. D. & According BERRy & S HiNE (1980), an SPOTiLA , J.