Journal of Bioscience and Applied Research,2016, Vol.2, No.7, PP.458-469 pISSN: 2356-9174, eISSN: 2356-9182 458 Journal of Bioscience and Applied Research WWW.JBSAR.com Morphological observations, length-weight relationships, and condition factors of the Whipfin fish, Gerres filamentosus (Cuvier, 1829) in the Hurghada Red Sea, Egypt Taher M. Abu El-Nasr Zoology Department, Faculty of Science, Zagazig University, Egypt (Corresponding author-email: [email protected]) specimens were healthy and in good condition due to Abstract spawning cycle or other physiological activities or During the period from January 2010 to December 2010, environmental factors. In searching of new potential the biometric studies of 669 (both sexes- 12:39 aquaculture marine species, Gerres filamentosus may centimeters) the whipfin, silver biddy, Gerres play role for enhancement of fish production as well as filamentosus (Cuvier,1829) have been described to clarify upliftment of socioeconomic condition in Egypt. the identity of the fish population in the Hurghada Red Sea, Egypt. The straight lines of the regression equations Keywords: Gerres filamentosus, morphometry, Length- of twenty one morphometric measurements relative to the Weight, Condition Factor total length or the head length indicate the linear relationships of the different body parts. Significant 1. Introduction curvilinear relationship existed between total length and Nelson (1994) listed 40 species belonging to 8 genera other morphometric characters and between head length such as Dipterous, Eucinostomus, Eugerrenes, Gerres, and other characters of the head. Relationships between Paregueila, Pentaprion, Ulaema and Xystaema in the total length and various body measurements of the fish world waters. were highly significant (p < 0.01) except the relationship Fishes belonging to the family Gerreidae are small to between total length and 2nd spine dorsal fin length of fish moderate in size, brightly colored, and inhabit near-shore (p < 0.05). The Meristic characters including the number waters with sandy substrate (El-Agamy, 1988). They are of fin rays, lateral line scales and gill rakers were found widely distributed in tropical and sub-tropical waters in to be more or less similar except slight differences. The many parts of the world (Cyrus and Blaber 1982 and length-weight relationships respect to the total or the Araujo et al., 1999). Until now, about 44 species of gutted weight were also investigated. It is obvious that, Gerreid fishes were recognized worldwide (Nelson, 2006; the value of the exponent (n=2.9475) indicates the Rodriguez-Romero et al., 2008), ten of which were negative allometric growth of this species. The values recorded in the coastal waters of China (Shen, 1993 and of condition factors (kc) in the total length body-weight Wu et al., 1999). The majority of species are benthic relationships for female , male and combined sexes were dwellers in the tidal areas of estuaries and very shallow found to be 1.49 , 1.47 and 1.51, respectively. The mean coastal water. values of relative condition factors (kn) were 1.03 , 0.97 Fish are said to be isometric growth when length and 1.00 for female , male and combined sexes, increases in equal proportions with body weight for respectively. However, relative condition factor (Kn) constant specific gravity. The regression coefficient for of Gerres filamentosus computed for July was 1.116 ± isometric growth is ‘3’ and values greater or lesser than 0.24 and for January was .934 ± 0.012, which suggest the ‘3’ indicate allometric growth ( Le Cren , 1951). Thus ‘k’ Journal of Bioscience and Applied Research,2016, Vol.2, No.7, PP.458-469 pISSN: 2356-9174, eISSN: 2356-9182 459 factor measures the variations from an ideal fish, which carrying out research especially on taxonomy, racial study holds the cube law while ‘Kn’ measures the individual and morphology of other fish species in Egypt. deviations from the expected weight derived from the 2. Materials and Methods length-weight relationship. There are no known species- For the biometric study, a random fresh samples specific conservation measures in place for Gerres of 669 individuals of the whipfin fish Gerres filamentosus. However, there are several marine protected filamentosus (Cuvier,1829), raning in total length between areas within its distribution (Feary, et al., 2015) . Gerres “12” and “39”centimeters from the commercial catch of filamentosus prefers tropical to temperate seas, which is Hurghada Red Sea ,Egypt(New lengths were recorded of most often encountered solitary or in small schools this species ) in the period from January 2010 to (Randall, 1995) and adults of this species tend to inhabit December 2010 were examined. Measurement of shallow coastal waters with either sandy bottoms or coral- different body dimensions of “257”and “412” line areas; Gerres filamentosus is most often caught with individuals of males and females, respectively were beach seines and trawls and is sometimes caught as by recorded by the aid of a divider on the left side of the fish, catch (Carpenter, et al. 1997). Gerres filamentosus may with the help of a fish-measuring board having divisions enter lakes; the maximum recorded total length (TL) is 35 up to 0.1 cm. The length measurements were pooled for cm (Roux, 1986) and lower freshwater reaches of rivers; each month and analyzed, keeping the size intervals as 0.9 it is marketed fresh in most cases, but can be salted or cm. For the morphometric identification the twenty one turned into fish sauce (Woodland 2001). Juveniles are measurements were taken which are: Total length(T.L.), found in brackish mangrove estuaries; sometimes enter fork length (F.L.), standard length(S.L.), body fresh water and tidal creeks (Allen, 1991, Allen, et al. depth(B.D.), head depth(H.D.) , head length (H.L.), snout 2002). length (Sn.), anterior point of snout to first dorsal spine- Gerres filamentosus forms part of a species Pre-Dorsal Length( Pr.D.L.), pre-pectoral complex and recently new species has been described length(Pr.Pec.L.), pre-pelvic length(Pr.Pv.L.), Pre-anal (Iwatsuki et al. 2002). Therefore some records of this length( Pr.A.L.), 2nd dorsal spine -when found( 2nd D.S.), species may be confused with these (Gerres infasciatus, eye diameter(E.D.),pre-Orbital length(Pr.O.L.), post- G. macracanthus and G. microphthalmus). Formerly Orbital length( Pt.O.L.), mouth width (M.), dorsal fin known from Philippines, Indonesia, New Guina, India and length (D.F.L.), caudal fin length(C.F.L.), pectoral fin the Arabian Gulf, Gerres macracanthus is newly- length(Pec.F.L.), pelvic fin length(Pv.F.L.), anal fin recorded from Japan, China, the Gulf of Thailand, the Red length(A.F.L.). Length measurements were taken in Sea and South Africa. A lectotype and three centimeters with two decimal place correction by using paralectotypes are designated to a neotype for Gerres measuring board and measurement tape. Five filamentosus(Cuvier,1829) (Iwatsuki et.al,1996). meristic characters were determined on the pooled sexes Seasonal variations in water clarity indicate that for ’69’ whipfin, silver-biddy fish, Gerres filamentosus mangroves were the preferred settling habitats for Gerres (Cuvier, 1829) of ‘29’ males and ‘40’ females. Meristic filamentosus, especially during the dry period before the characters including the number of fin rays, lateral line rainy season (Lugendo et. al., 2007).Moreover, the scales and gill rakers were recorded statistically according relationship of fish abundance and species diversity to to Snedecor,( 1956). water temperature and salinity differed among estuaries Weight measured in grams by electric balance with (Tzeng et. al., 2002). Meristic and morphometric two decimal place correction. Fishes were identified characters and the differences between the three gerreids according to Whitehead et al. (1984). Length-weight known from Iraqi waters [G. filamentosus Cuvier, 1829, relationships were calculated using the least squares G. oyena (Forsskål, 1775), and G. longirostris (Lacepède, regression on log transformation of the equation: 1801)] are discussed by Ali et al., 2014. They added a W = a Ln (Beckman,1948 and Le Cren,1951) new records of Gerres limbatus bring the total number of where: Gerres species in Iraq to four. Additionally, two new size W is the total weight (in gm) and L is the total records are reported for this species. By using Principal length (in cm). Component Analyses (PCA) to Clarifying the high a is a constant and n is an exponent. similarity between fish species on the morphometric and The systematic bias of the logarithmic the morphological characters, and genetic distance of the transformation was corrected according to Sprugel specimens showed that Alburnus adanensis should be (1983). Eviscerated weight (gutted weight) was used in evaluated as a synonym of Alburnus sellal which inhabit all calculations of indexes to avoid any influence of the Turkian river basins (Birecikligil et. al, 2016). contents of the gonad and stomach on the weights. However, very limited information is available so far on the length-weight relationship and condition factor of 3. Results and Discussion Gerres filamentosus in the world and therefore, the Description: present study was undertaken to establish the pattern of The external features of Gerres filamentosus growth and general condition of this fish species from the (Cuvier,1829) was described as follows: The second natural waters of Hurghada Red Sea, Egypt for direct use dorsal spine is laterally compressed, produced into a in fishery assessment. This work would also contribute filament, whose tip extends and past the level of first anal to the existing knowledge by acting as a baseline data for spine. It`s body depth contained 2 to 2.5 times in standard length in larger specimen, up to 3 times in smaller Journal of Bioscience and Applied Research,2016, Vol.2, No.7, PP.458-469 pISSN: 2356-9174, eISSN: 2356-9182 460 specimen.