Morphological variability of the baculum in  Martes foina  (Carnivora: Mustelidae) from Turkey

Ahmet Haris Selçuk ÖZEN

doi:10.3906/zoo-1802-39

Abstract

The present study was based on the bacula of 39 male (17 juvenile, 22 adult) stone marten (Martes foina) samples obtained from all geographical regions of Turkey between 1995 and 2016. Morphological variability in 11 characteristics of bacula was investigated. The purpose of this study was to measure numerical characters of the baculum, to identify relationships between measurements, and to evaluate variabilities in its morphology. Weight, total length, base length, base height, base width, apex height, apex width, median width, and median height were significantly greater in the bacula of adults compared to the bacula of juveniles. The most variable characteristic in adults was base width (18.96%). There was a significant relationship between some characteristics of the bacula measured. The strongest positive relationships were observed between median height and baculum weight (r = 0.771), weight and base length (r = 0.755), and median width and weight (r = 0.750) characteristics. Statistical analysis (PCA) also revealed a strong relationship between some characteristics. In particular, positive correlations between width and height sizes in the base (proximal), median, and distal of the baculum, as well as axis?apex height and apex width, suggest relationships that protect the urethra and baculum from fissures and fractures during copulation.

Highlights

The coefficient of variance (CV) is an indicator of the characteristic of variability and was identified only for adult samples
The results showed that the most variable characteristics of the baculum were base height, axis–apex height, weight, and width of base; the least variable characteristics were total length, median height, median width, apex height, and apex width (Table 2)
As in other mammal species (Reinwaldt, 1961; Sumiński, 1968; Walton, 1968; Buchalczyk and Ruprecht, 1977; Miller and Burton, 2001), this is characteristic for stone marten

Summary

Introduction

The baculum (os penis) is an extraskeletal bone located in the glans tissue at the distal end of the penis and is present in several mammalian species, including the order Carnivora (Patterson and Thaler, 1982; Abramov, 2002; Baryshnikov et al, 2003; Ferguson and Larivière, 2004; Ramm, 2007; Krawczyk and Malecha, 2009; Krawczyk et al, 2011; Vercillo and Ragni, 2011; Čanády and Onderková, 2016a, 2016b). The morphological structure of the baculum is specific to the species. It is used as a distinctive characteristic to distinguish between species (Baryshnikov et al, 2003; Schulte-Hostedde et al, 2011; Sharir et al, 2011; Vercillo and Ragni, 2011). The functions of the baculum are to provide support during erection (Kelly, 2000), to protect the urethra (Baryshnikov et al, 2003), to stimulate the female reproductive tract during copulation (Krawczyk and Malecha, 2009), to ensure reproductive isolation between species, and to be an indicator of the male’s condition (Čanády and Čomor, 2013).

Objectives

Methods

Results

Conclusion