Geometry Morphometry and Health Status of Hawksbill Turtle (Eretmochelys imbricata Linnaeus, 1766) in Maratua Island, East Kalimantan-Indonesia

Abstract

Research on hawksbill turtles in the Maratua Island is still very few. Meanwhile, population of hawksbills was believed to decline due to human exploitation. The aim of this research was to study the morphology of hawksbill through geometric morphometric approach and health status which includes the existence of epibionts, mechanical damages and Body Condition Index. The survey was conducted from 5 to 18 September 2014. The method used was the hand-catching by snorkeling and diving for catching turtles, morphometric measurements and documentation of the turtle body parts using the camera. Morphological aspects were analyzed with linear regression and geometry approach with Microsoft Excel and ImageJ software. Health status was analyzed with observation of epibionts and mechanical damages through photos and calculation of Body Condition Index. There were 11 turtles that have been caught. The results indicated the growth of straight carapace length notch to tip affect the growth of the other body parts of hawksbill turtle and based approach to geometry, shape growth of hawksbill turtles that are found in Maratua not changed but only have added size. Based on the health status through observation epibionts, mechanical damages and analysis of Body Condition Index, hawksbill in Maratua still relatively healthy compared with studies elsewhere.

Blood analytes of hawksbill sea turtles (Eretmochelys imbricata) from Florida waters: reference intervals and size-relevant correlations

“…10.3389/fevo. 2023.1199688 Frontiers in Ecology and Evolution 07 frontiersin.org BCI of all hawksbills in this study ranged from 0.94-1.39 (mean ± SD: 1.13 ± 0.10), which is similar to two aggregations of hawksbills from Puerto Rico (means of 1.16 and 1.18) (Diez and van Dam, 2002) and the Bahamas (mean ± SD: 1.17 ± 0.08; range: 1.05-1.41) (Bjorndal and Bolten, 2010), but higher than hawksbills from Indonesia (mean ± SD: 1.06 ± 0.07; range: 0.92-1.14) (Maulida et al, 2017), and lower than hawksbills from the Monito cliff wall in Puerto Rico (mean: 1.24) (Diez and van Dam, 2002) and the Cayman Islands (Little Cayman mean ± SD: 1.25 ± 0.17; Grand Cayman mean ± SD: 1.24 ± 0.18) (Blumenthal et al, 2009). Norton There is evidence that hawksbill turtles migrate during their development and growth from small juveniles in the Florida Keys along the Southeast Florida Continental Reef Tract to subadults in their northern range in Palm Beach County, Florida (Wood et al, 2013).…”

“…These findings are endpoints needed for defining inclusion criteria in wild animal studies. In fact, some health assessment studies are solely based on physical examination and morphometric measurements (Maulida et al, 2017). All hawksbills captured during the study time frame fit the inclusion criteria for the study.…”

Differences in the morphological body condition index of sea turtles between species and size classes

“…Fulton's condition index has been widely applied in sea turtle studies, excluding flatback turtles ( Natator depressus ). Values of Fulton's condition index based on SCLs ≥1.2 have been interpreted to indicate a relatively good body condition for sea turtles (Norton & Wyneken, 2015; Maulida et al ., 2017; Adnyana et al ., 2020). Although index values ≥1.3 were generally observed in large green and loggerhead turtles, the meta-analysis in this study supported the adequacy of this threshold for juvenile and adult green turtles and large juvenile and adult loggerhead turtles.…”

“…Interspecific or interpopulation comparisons are also difficult when body dimensions or growth patterns differ. In sea turtles, Fulton's condition index has been widely used as a rough measure of nutritional status and health (Bjorndal et al ., 2000 a ; Diez & van Dam, 2002) and values exceeding 1.2 have conventionally been interpreted to indicate a good body condition (Norton & Wyneken, 2015; Maulida et al ., 2017; Adnyana et al ., 2020). However, the threshold value may change, considering that there are interspecific and/or intraspecific differences in the body shape and growth pattern of sea turtles (Wabnitz & Pauly, 2008; Álvarez-Varas et al ., 2019).…”

Digital image processing: A new tool for morphological measurements of freshwater turtles under rehabilitation

“…The utility of ImageJ in analyzing animal morphology has been well-demonstrated in prior research. Maulida et al [ 56 ] conducted a study that utilized ImageJ for the analysis of Hawksbill Turtle carapaces. Their findings highlighted the efficiency and accuracy of ImageJ in assessing carapace curvature and various other morphological attributes, including size and shape.…”