Morphological Anomalies Observed on Vertebralina striata dOrbigny, 1826 Test in the Northern Coast of Karaburun Peninsula (Izmir-Turkey)

Abstract

Morphological abnormalities have been observed on the test of recent foraminifer samples and locally different ecological conditions are suggested to be the cause of this phenomenon. Hypersalinity, presence of heavy metals, thermal springs, chemicals carried by the coastal and submarine springs found in karstic regions and rapid change in ecological parameters are suggested to play a major role in changing the ecological conditions that leads to abnormal test morphology in foraminifers. Abnormal test development, as well as twins and triplets are commonly observed in natural and artificial saltpans which form hypersaline environments. Submarine freshwater springs can cause extreme seasonal salinity variations on the coastal regions which affects the benthic foraminifer species and results in the abnormal test development. Vertebralina striata d Orbigny individuals with abnormal aperture morphology have been found in samples collected around the thermal springs in Cesme-Ilica Bay. More surprisingly, specimens with similar aperture abnormality have also been observed in samples collected from other two stations on the Karaburun Peninsula. Five of the abnormal specimens had two apertures the others had three. A specimen collected from Ilica Bay had two apertures, one of which is the typical Vertebralina striata d Orbigny aperture, but the other was distantly located and rounded. Vertebralina striata d Orbigny is widely distributed in world s seas, however such aperture abnormalities has not been reported elsewhere. Observation of similar morphological abnormalities in three distinct locations suggests a common cause. The submarine spring found in Ilica Bay supports the idea that spring waters affect the chemical composition of the seawater locally, leading to this aperture abnormality.