Sexual dimorphism in head size of the Mediterranean gecko Hemidactylus turcicus (Sauria: Gekkonidae)
Sexual dimorphism in head size of the Mediterranean gecko Hemidactylus turcicus (Sauria: Gekkonidae)
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地中海壁虎 Hemidactylus turcicus（蜥目：壁虎科）头部大小的性别二态性
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
R. Conner
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文献类型：
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作者：
Daniel Sáenz;R. Conner
-对从德克萨斯州纳科多奇斯斯蒂芬奥斯汀州立大学校园收集的 53 只雌性和 67 只雄性地中海壁虎 (Hemidactylus turcicus) 进行了比较。将成年雄性和雌性的头部尺寸（长度、深度和宽度）和体重与使用吻部通气长度作为协变量的协方差分析进行比较。在给定的口鼻部长度下，雄性的头部尺寸和重量明显更大。雄性和雌性的口鼻部长度没有显着差异。雄性较大的头部可能是性选择的结果，因为具有较大头部的雄性在异性恋和无性恋中可能表现出更大的成功。雌性体型较大也可能具有生态优势，导致两性体型平行增加。较大的雌性可能会产生质量更好的卵，这可能会提高后代的存活率。地中海壁虎 Hemidactyhs turcicus 是一种原产于旧大陆的外来蜥蜴，最近（自 1920 年代以来）在美国海湾沿岸国家定居（Stejneger 1922；Conant & Collins 1991）。先前发现的壁虎性别差异包括成熟雄性的肛前毛孔和泄殖腔后骨增大，而这些在未成熟的雄性和雌性中并不明显（Selcer 1986）。本研究旨在检验成年雄性和雌性 H. turcicus 之间的体型二态性以及与其起源相关的可能因素。众所周知，地中海壁虎会用尾巴进行行为展示。 Klawinski (1991) 观察到一只雄性壁虎在进行侵略性的性内接触时摇动尾巴，而 Marcellini (1977) 观察到一只雄性壁虎向雌性摇动尾巴，显然是在求爱。尽管已经观察到尾巴摆动，但对该物种的研究还很少。没有对两性之间尾长差异的调查。头部大小二态性在有鳞动物中很常见，是一种可能受到生态隔离和性选择影响的特征（Shine 1991）。 Camilleri & Shine (1990) 认为，某些蛇的头部大小二态性是猎物大小特化的形态适应的结果。蜥蜴的头大小二态性通常为 208 德克萨斯科学杂志-卷。 48，没有。 1996 年 12 月 3 日 表 1. 成年地中海壁虎的形态测量。 N 平均值 f S D 调整范围 平均值 SVL (mm) 男性 女性 头部长度 (mm) 男性 女性 头部宽度 (mm) 男性 女性 HEi,深度 (mm) 女性 尾部长度 (mm) 男性 女性 w;jtt’ hi!) 女性 5637 50.9 * 3.77 ~ 44.0 58.0 51.5 f 4.45 44.0 60.0 :i 12.4 rt 1.13 12.5 10.0 15.0 12.2 + 1.20 12.2 8.0 14.0 英尺 10.1 f 0.90 10.1 8.0 12.0 9.7 f 0.99 9.7 7.0 12.0 6.5 0.84 4.0 8.0 6.1 0.86 2:: 4.0 8.0 52 52.4 6.31 52.4 31.0 64.0 42 51.0 8.47 50.9 28.0 66.0 3.5 * 0.94 1.9 5.8 3.4 f 1.02 1.4 5.6 归因于性选择或资源防御，其中头部较大的男性在性内对抗中更成功（Carothers 1984；Vitt & Cooper 1985；Hews 1988；Smith 1992；Mouton & Wyk 1993）。方法和材料 壁虎采集于德克萨斯州纳科多奇斯县纳科多奇斯的斯蒂芬·F·奥斯汀州立大学校园（西经 94 英寸，北纬 3 1 英寸）。所有壁虎 (N = 200) 均在 1990 年 4 月 19 日至 10 月 15 日的 1844 年至 0045 点之间的日落后采集。收集了采样过程中遇到的前 15 只壁虎。将标本送回实验室，用游标卡尺测量口鼻孔长度 (SVL)、头部长度（从头骨底部到口鼻尖测量）、头部深度（从头部最深部分测量）、头部宽度（从头部最宽部分测量）和尾长（从口鼻孔到尾尖测量），测量精确到 1 .O mm，并称重，精确到 0.1 g。所有壁虎在保存前都经过测量（和称重）。 2 44 mm SVL 的个体被视为成年人（Selcer 1986）。所有尾巴断裂或再生的蜥蜴均被排除在测试之外
-Comparisons were made between 53 female and 67 male Mediterranean geckos (Hemidactylus turcicus) collected from the campus of Stephen F. Austin State University in Nacogdoches, Texas. Head dimensions (length, depth and width) and weight of adult males and females were compared with analysis of covariance using snout-ventlength as a covariate. Males were significantly larger in head size and weight at a given snout-vent-length. Males and females did not differ significantly in snout-vent-length. Larger heads in males may be the result of sexual selection, as males with larger heads may exhibit greater success in i&asexual encounters. There may also be an ecological advantage for larger body size in females resulting in parallel increases in body size in both sexes. Larger females may produce better quality eggs which may enhance survival rates in offspring. The Mediterranean gecko Hemidactyhs turcicus is an introduced lizard native to the Old World that has recently colonized (since the 1920s) the gulf coastal states of the U. S. (Stejneger 1922; Conant & Collins 1991). Some previously identified sexual differences in the gecko include enlarged preanal pores and post-cloacal bones in mature males that are not obvious in immature males and females (Selcer 1986). This study was undertaken to examine body-size dimorphism between adult male and female H. turcicus and possible factors related to its origins. The Mediterranean gecko is known to use its tail in behavioral displays. Klawinski (1991) observed a male gecko tail-waving while engaged in an aggressive intrasexual encounter, while Marcellini (1977) observed a male gecko tail-waving at a female apparently in a courtship display. Although tail-waving has been observed, it is not well studied in this species. There are no investigations into tail-length differences between the sexes. Head-size dimorphism, which is common in squamates, is a trait that may be influenced by both ecological segregation as well as by sexual selection (Shine 1991). Camilleri & Shine (1990) suggest that head-size dimorphism in some snakes is the result of morphological adaptations for prey-size specialization. Head-size dimorphism in lizards is usually 208 THE TEXAS JOURNAL OF SCIENCE-VOL. 48, NO. 3, 1996 Table 1. Morphological measurements of adult Mediterranean geckos. N Mean f S D Adjusted Range Mean SVL (mm) male female Head length (mm) male female Head width (mm) male female HEi,depth (mm) female Tail length (mm) male female w;jtt’ hi!) female 5637 50.9 * 3.77 ~ 44.0 58.0 51.5 f 4.45 44.0 60.0 :i 12.4 rt 1.13 12.5 10.0 15.0 12.2 + 1.20 12.2 8.0 14.0 FT 10.1 f 0.90 10.1 8.0 12.0 9.7 f 0.99 9.7 7.0 12.0 :; 6.5 f 0.84 4.0 8.0 6.1 f 0.86 2:: 4.0 8.0 52 52.4 f 6.31 52.4 31.0 64.0 42 51.0 f 8.47 50.9 28.0 66.0 3.5 * 0.94 1.9 5.8 3.4 f 1.02 1.4 5.6 attributed to sexual selection or resource defense where males with larger heads are more successful in intrasexual confrontations (Carothers 1984; Vitt & Cooper 1985; Hews 1988; Smith 1992; Mouton & Wyk 1993). M ETHODS AND M ATERIALS Geckos were collected on the campus of Stephen F. Austin State University in Nacogdoches, Nacogdoches County, Texas (94”W longitude and 3 1 “N latitude). All geckos (N = 200) were taken after sunset between 1844 and 0045 hrs from 19 April to 15 October 1990. The first 15 geckos encountered during a sampling session were collected. Specimens were returned to the lab where snout-vent-length (SVL), head length (measured from the base of the skull to the tip of the snout), head depth (measured from the deepest part of the head), head width (measured from the widest part of the head), and tail length (measured from the vent to the tip of the tail) were measured to the nearest 1 .O mm with dial calipers, and they were also weighed to the nearest 0.1 g. All geckos were measured (and weighed) before they were preserved. Individuals 2 44 mm SVL were considered adults (Selcer 1986). All lizards with broken or regenerated tails were excluded from testing for