Biometry of the Fishes Barbus Plebejus and Barbus Capito from Coruh Basin, Turkey

Metric and meristic characters are important to identify fish species and their habitat peculiarities. There are many species that belong to the fish genus Barbus, which is found in tropical and extratropical regions, but there are few studies covering the Coruh basin. Two subspecies of Barbus were found in the Coruh River system of Eastern Anatolia, Turkey: Barbus plebejus escherichi and Barbus capito capito. We collected specimens in seven localities for measurement. The number of vertebra were determined radiographically. Some specimens of B. capito capito have a sharper snout in the segments of Coruh where the water flows faster, suggesting a modification related to current. The biometric measurements vary geographically and could be related to abiotic and biotic factors in the habitat. Metric and meristic characters are important to identify fish species and their habitat peculiarities as well as ecological criteria in any stream, lake or sea (Karaman 1971, Geldiay and Balık 1998, Karatas 2005). A variety of morphological, physiological, behavioral and biochemical characteristics are used to identify and classify fishes. in practice though, it is more common to use morphometric measurements (i.e., body length, body depth, head length, eye diameter, jaw length) and meristics (i.e., fin ray, scale, teeth, gill raker, and lateral line pore counts). These morphometric measurements are usually presented as a proportion of standard, fork and total length (Howe 2002). There are limited studies concerning this topic in Coruh basins (Karaman 1971, Kuru 1975). Two subspecies of Barbus were found in the Coruh River system of Eastern Anatolia, Turkey. These are Barbus plebejus escherichi Steındachner, 1897 and Barbus capito capito Guldenstadt, 1773. The purpose of the present study is to contribute to the knowledge of the biometric measurements and their relationships to Barbus plebejus escherichi and Barbus capito capito inhabiting Coruh Basin from Turkey. MATERIALS AND METHODS This study was based on specimens collected from Coruh Basin (Fig. 1). Samples were caught by using electroshocker in 7 localities. Metric characters of fishes were measured by using compass and ruler, and meristic characters were determined under binocular microscope and magnifier. The number of vertebra were determined radiographically

Metric and meristic characters are important to identify fish species and their habitat peculiarities as well as ecological criteria in any stream, lake or sea (Karaman 1971, Geldiay and Balık 1998, Karatas 2005).A variety of morphological, physiological, behavioral and biochemical characteristics are used to identify and classify fishes. in practice though, it is more common to use morphometric measurements (i.e., body length, body depth, head length, eye diameter, jaw length) and meristics (i.e., fin ray, scale, teeth, gill raker, and lateral line pore counts).These morphometric measurements are usually presented as a proportion of standard, fork and total length (Howe 2002).
There are limited studies concerning this topic in Coruh basins (Karaman 1971, Kuru 1975).Two subspecies of Barbus were found in the Coruh River system of Eastern Anatolia, Turkey.These are Barbus plebejus escherichi Steındachner, 1897 and Barbus capito capito Guldenstadt, 1773.
The purpose of the present study is to contribute to the knowledge of the biometric measurements and their relationships to Barbus plebejus escherichi and Barbus capito capito inhabiting Coruh Basin from Turkey.

MATERIALS AND METHODS
This study was based on specimens collected from Coruh Basin (Fig. 1).Samples were caught by using electroshocker in 7 localities.Metric characters of fishes were measured by using compass and ruler, and meristic characters were determined under binocular microscope and magnifier.The number of vertebra were determined radiographically    by using convenient x-rays dosages.Findings were statistically calculated by using SPSS programme.
Determining of metric characters for Barbus species and supspecies are shown in Figure 2.
This research covers the variations of the ratios HH/HL, IO/HL, PO/HL, HL/TL, AnD/ TL, DD/TL (Fig. 2), their X, S, V, F values (Tables 1 and 2).The identifications of these abbreviations are given in each table.Moreover, meristic characters of two subspecies of Barbus were found out in this paper (Table 3).
Meristic measurements of each subspecies (Table 3), and metric and meristic characters of different Barbus species, according to various authors, are also given (Table 4).

RESULTS
Dorsal fin rays, the vertebrate film and pharyngeal teeth of B. plebejus escherichi are given in Fig. 3, 4 and 5, respectively.Our findings regarding metric characters are given in Table 1 and Table 2. Meristic characters are given in Table 3.
The number of gill rakers (8-12) of B. plebejus escherichi recorded by Karaman (1971) is different from our findings (12-16) as seen in Table 3.On the other hand, the results in the number of gill rakers noted by Karaman (1971) for B. capito capito is the same as our findings in this study (13)(14)(15).
According to Nicolsky (1963), there are certain anatomical modifications regarding the particular function of the first three fin rays.The number of branchial spins recorded by Kuru (1975) is very close to the number recorded for B. plebejus escherichi and B. capito capito in this study.
We have specimens of B. capito capito which show a sharp nose in the segments of Coruh where the water flows faster, suggesting a modification related to the speed of the water current in the river.All the morphological differences are possibly due to the variability of the habitats (Nicolsky 1963).Our results show that the biometric measurements are different from each other for the same species in the present study.These findings mean that this could be related to abiotic and biotic factors in the habitat.
The importance of our study is indirectly supported by Kosswig's (1969) and Stewart (1977).

TABLE 1A Biometric measurements of Barbus plebejus escherichi in various localities of the Coruh Basin
n = sample size, HH =head height, HL = head length, IO = interorbital width.

TABLE 1B
Biometric measurements of Barbus plebejus escherichi in various localities of the Coruh Basin

TABLE 1C
Biometric measurements of Barbus plebejus escherichi in various localities of the Coruh Basin n = sample size, An D = anal distance, TL = total length, DD = dorsal distance.

TABLE 2A
Biometric measurements of Barbus capito capito in various localities of the Coruh Basin

TABLE 2B
Biometric measurements of Barbus capito capito in various localities of the Coruh Basin n = sample size, PO = proorbital length, HL = head length, TL = total length.

TABLE 2C
Biometric measurements of Barbus capito capito in various localities of the Coruh Basin n = sample size, An D = anal distance, TL = total length, DD = dorsal distance.

TABLE 3
Some meristic measurements of Barbus supsecies in Coruh Basin