Trochiscia hamzaoglui (Chlorellales): A New Species from Central Anatolia (Turkey)

A new species, Trochiscia hamzaoglui Atıcı sp. nova, determined from freshwater habitat, Kesikköprü Dam Lake on the Kizilirmak River (Kirşehir, Central Anatolia), and the sample was taken from plankton. This new species was first found in the study of algal samples from the area. Light microscope indicated a clear relationship with the species in the genus Trochiscia. Some of the characteristic features of the new taxon include a spine and an irregular cell wall. A comparison with closely related taxa is given on.


Introduction
Trochiscia Kütz.(Oocystaceae, Chlorellales) was first detected by Kützing as four species: T. solitaris Kützing, T. dimidiate Kützing, T. quadrijuga (Turpin) Kützing and T. elliptica Kützing [1].Trochiscia is not widespread worldwide and occurs in the phytoplankton of bogs, ponds and lakes, especially in acidic waters.Almost all taxa are freshwater, although a few marine species have been reported [2].Trochiscia species have shown variations in pyrenoid number, construction, cell size and shape, indicating that the genus is much more morphologically diverse than previously thought.
Cells are spherical to sub-spherical and solitary (sometimes gregarious).The cell wall is thick and bears spines or is irregular and variously sculptured (e.g.ridged and sharp spines).The chloroplast is parietal, usually lobed and has one pyrenoid (spine-bearing species), or one to several parietal disks and one pyrenoid (sculptured species).The same species occur in snow and also terrestrially.They are fairly common, with different species colonising aquatic, terrestrial and snow habitats [3]- [6].
Trochiscia plankton is permanent or semi-permanent in freshwater systems, especially in temperate waters of the Northern Hemisphere, with numerous reports from Europe and North America.The genus is also placed in Oocystaceae by some authors.

Methods
Kesikköprü Dam Lake is located in Kırşehir above 750 m elevation and is 650 ha in size.The maximum depth is 30 m [7] [8].The lake was built in 1959 on the Kızilirmak River in the Central Anatolian region of Turkey for irrigation and power generation purposes.Study area have continental climate which is relatively dry climate with hot summers and cold winters.The study area lies at 39˚22'53E to 39˚22'54E longitude and 33˚25'14N to 33˚28'13N latitude.The aquatic samples were collected from Kesikköprü Dam Lake in May 2009-2010.Collections were from different localities in the dam lake and from depths ranging from 50 cm near the shore to 25 m at the centre.Each sample was kept in a plastic container filled with the lake water to which 5 mL of 4% formalin was added [9].
Plankton samples were collected twice a month from selected stations of the Dam Lake (Figure 1) and transferred to the laboratory for microscopic studies.The phytoplankton samples were collected with Nansen water collecting by Hydrokiel (45 μ mesh size) apparatus.Water samples for measuring environmental parameters were collected by filling one litre plastic jar with the lake water.
Determination of some physical and chemical properties (pH, temperature, oxygen and light porous effect) was reported (Table 1).Water temperature, oxygen, light porous and pH were measured at the time of sampling, with a portable tester YSU using YSI 6600 multiple probe [10].Freshwater samples of the materials were stored in formaldehyde solution, and herbarium numbers of the species of algae examined are listed in Gazi MACC (Gazi University Microalgal Culture Collection) [11].Identification of species was carried out by examination  under a research light microscope (LM) [3]- [6], slides and preserved material were examined with a Nikon FX microscope equipped with a Nikon DXM 1200 (Nikon, Tokyo, Japan), and photographs were taken.

Environmental Parameters
The water of Kesikköprü Dam Lake is highly alkaline (pH 8.10) with water temperature being between 4˚C -22.2˚C and oxygen level between 8.04 -11.2 mg•l −1 (Table 1).According to some physical-chemical properties, this species can exist in a wide range of temperatures, and prefers high-level oxygen and alkaline areas.Kesikköprü Dam Lake waters take in freshwater from high mountains and also from snow.

Specimens of Related Species Examined
Trochiscia hamzaoglui was described (Figure 2) from a freshwater planktonic habitat, Kesikköprü Dam Lake in the Central Anatolian region of Turkey, and was under observation for two years.Using morphological, cytological and ecological characters [12]- [14], this species was shown to have some differences from the other Trochiscia members [15]- [19].
The species is differentiated by details of cell morphology, especially the structure and ornamentation of the cell walls (Table 2).Many descriptions of Trochiscia species require culturing to confirm their assignment to this genus, as many taxa may represent zygospores or aplanospores of the other Chlorophycean algae.2) Holotype Turkey-Kırşehir: Kesikköprü Dam Lake, 29˚23.283'N-33˚25.593'E.Permanent samples deposited in the Gazi.MACC (Gazi University, Ankara, Turkey) are materials collected as phytoplankton (known only from type locality).

New Species Description
Type material Planktonic sample, collected in June 12, 2010.

Etymology
This new species is named in honour of the Turkish Botanist Prof. Dr. Ergin Hamzaoğlu (Biology Education Department, Gazi University, Ankara).

Morphometry
Trochiscia hamzaoglui is described in Figure 2. It is shown to have some differences from the other Trochiscia members [20]- [23].The key of the genara Trochiscia is consolidated in this new species (Table 3).

Table 1 .
Some physical and chemical parameters of Kesikköprü Dam Lake.

Table 2 .
Comparison of characters for selected members of Trochiscia.
3.Cell with reticulate covered with fine short spines and wide spines like thorn Trochiscia verrucosa 4.Cells with reticulate ornamentation and long spines including lots of pyrenoid Trochiscia hystrix 4.Cells with reticulate covered papillae, often within a thin mucilaginous envelope Trochiscia planctonica