. The Canadian field-naturalist. . Figure 3. Green Turtle-Loggerhead Turtle hybrid found in St. Margarets Bay, Nova Scotia, on 2 Ociobci 2(J(Jl. 1 he l^n^c pair of prefrontal scutes on the head (left) are characteristic of Chelonia inyclas. However, overlapping costal and vertebral scutes and strongly serrated marginal scutes (right) are not characteristic of Chelonia mydas. et al. 1995). In addition to the results presented here, there is only one previous repoit of hybridization between a Loggerhead Turtle and a Green Turtle (Karl et al. 1995). Hybridization between the Carettini and Cheloni
. The Canadian field-naturalist. . Figure 3. Green Turtle-Loggerhead Turtle hybrid found in St. Margarets Bay, Nova Scotia, on 2 Ociobci 2(J(Jl. 1 he l^n^c pair of prefrontal scutes on the head (left) are characteristic of Chelonia inyclas. However, overlapping costal and vertebral scutes and strongly serrated marginal scutes (right) are not characteristic of Chelonia mydas. et al. 1995). In addition to the results presented here, there is only one previous repoit of hybridization between a Loggerhead Turtle and a Green Turtle (Karl et al. 1995). Hybridization between the Carettini and Chelonini is extraordinary given that these tribes have been genetically separated for 50 million years or more (Bowen et al. 1993; Dutton et al. 1996). It has been suggested that these may be the oldest vertebrate line- ages known to hybridize in nature (Karl et al. 1995). The reproductive status of marine turtle hybrids is not known; however, the identification of potential second-generation hybrids (Karl et al. 1995) suggests that at least some hybrids may be fertile. Reproductive viability in hybrids could have important biological consequences for the conservation of marine turtles (Karl 1996). Both turtles reported here were of the size class typ- ical of neritic foraging populations of Green Turtles (, straight carapace length >25 cm) (Musick and Limpus 1997). Therefore, these animals likely arrived in eastem Canadian waters from coastal foraging habi- tat off the northeastern United States, rather than from pelagic areas. Our current understanding of juvenile Green Turtle distribution in the northwest Atlantic suggests that these turtles occupy areas where sea surface temperature is normally higher than that of coastal Atlantic Canada. In the case of the hybrid turtle, the Loggerhead Turtle component of its genotype may have been responsible for directing the animal to higher latitudes for for- aging, as Loggerhead Turtles are commonly encoun- tered in Atlantic Canadian
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