Biometric variability of Hadwenius tursionis (Marchi, 1873) (Digenea, Campulidae) from the intestine of the bottlenose dolphin Tursiops truncatus (Montagu, 1821)

• Published in: Systematic parasitology 1995-01, Vol.30 (1), p.67-76
• Main Authors: Fernández, M., Balbuena, J. A., Pertusa, J. F., Raga, J. A.
• Format: Article
• Language: English
• Subjects: Campulidae; Digenea; Marine; Tursiops truncatus
• ISSN: 0165-5752; 1573-5192
• DOI: 10.1007/BF00009246

The species discrimination in the family Campulidae is largely based on morphometric characters (absolute measurements and ratios). To assess the variability of this characters we have studied the campulid species Hadwenius tursionis from four Mediterranean bottlenose dolphins Tursiops truncatus from the Western Mediterranean. In H. tursionis most absolute measurements differed significantly across the infrapopulations, showing high coefficients of variation. Only egg dimensions appeared to be fairly conservative. Body ratios were less than absolute measurements, but growth patterns did vary significantly between the infrapopulations studied. None of the ratios previously used in relation to other species of the family Campulidae indicated either isometric or allometric growth in this case. Only the ratios concerning the size of the gonads and the shape of the gonads and suckers showed isometry. It is concluded that absolute measurements and ratios should be used with caution in relation to the separation of species of the family Campulidae unless their intrinsic variability can be established beforehand.