Macroanatomic, light and scanning electron microscopic studies of the pecten oculi in the stork (Ciconia ciconia)

Abstract

This study was undertaken to investigate the pecten oculi of stork by using macroscopic, light and electron microscopic techniques. A total of 20 eyes that were obtained from 10 storks were used. The eyes were cleaned and isolated by dissection. After various procedures, four of the pecten oculi were examined by light microscope while the other four with an electron microscope. The remaining 12 eyes were assigned for macroscopic investigation. Pecten oculi of the stork were determined as accordion-like structures that originated from n. opticus, consisting of 15-17 plica and projecting up to 2/5 of the diameter of the bulbus oculi. Light microscopic examination revealed two types of blood vessels. Afferent-efferent vessels were larger in diamater (40-45 µm), fewer in numbers, and the capillary vessels were smaller in diamater (2-5 µm) and more in numbers. There were granules including amount of melanin pigment at the apical part of the pleats. These granules were fewer and scattered randomly on the basal part of the pleats. As a result, pecten oculi in the stork, which is a migrating bird, were determined to be similar to those of other diurnal birds.

Macroanatomic, light, and electron microscopic examination of pecten oculi in the seagull (Larus canus)

“…Location of pecten oculi of the seagull which is a diurnal bird was detected similar to the literature (Jasinski, ; Braekevelt, ; Braekevelt, ; Kiama et al, ; Braekevelt, ; Kiama, Maina, Bhattacharjee, & Weyrauch, ; Kiama et al, ; Rahman et al, ; Orhan et al, ; Gültiken, Y?ld?z, Onuk, & Karayigit, 2012; Rajab, ; Dayan & Ozaydın, ; Onuk et al, ; Pourlis, ). However, some differences were determined in terms of the size and pleat numbers.…”

“…Tucker () reported that the surface area of the pecten oculi increased with the pleat number being high (Tucker, ). It was observed that the number of 18–21 pieces of pleat found in the seagull is compatible with other diurnal birds (Braekevelt, ; Kiama et al, ; Rahman et al, ; Orhan et al, ; Rajab, ; Gültiken et al, ; Dayan & Ozaydın, ; Onuk et al, ; Pourlis, ).…”

“…In many sources, it was indicated that the pecten oculi contains a large number of blood vessels with varying density of capillary vessels (Nickel, Schummer, Seiferle, Siller, & Wight, ; Rahman et al, ; Orhan et al, ; Gültiken et al, ; Micali et al, ; Onuk et al, ). Crozier and Wolf () and Kiama et al () stated that the presence of a dense vascular network is intended to provide retinal circulation.…”

“…Pecten oculi has a curved shape in majority of the birds which hunt during daytime. The differences between bird species also depend on pleat thickness, number, shape, and size of curves (Rahman, Lee, Aoyama, & Sug?ta, ; Micali et al, ; Rajab, ; Onuk, Tütüncü, Alan, Kabak, & Gezer, ; Pourlis, ).…”

“…Up to date, there are studies conducted on many species such as fowl (Dieterich, Dietcrich, Spycher, & Pfautsch, ; Hodges, ), sparrow (Jasinski, ), red‐tailed hawk (Braekevelt, ), great horned owl (Braekevelt, ), American crow (Braekevelt, ), ostrich (Braekevelt, ; Kiama et al, ), duck (Scala, Corona, Mirabella, Perrella, & Pelagalli, ; Corona, Scala, & Perrella, ), black kite (Kiama, Bhattacharjee, Maina, & Weyrauch, ), jungle crow (Rahman et al, ), budgerigar (Micali et al, ), stork (Onuk et al, ), sparrow hawk (Rajab, ), and quail (Orhan, Ekim, & Bayraktaroglu, ; Pourlis, ). There is not any article on pecten oculi morphology of the seagull which is a migratory water bird hunting diurnally, therefore, the present study was designed.…”