Morphological diversity of Sillaginid larvae (Perciformes: Sillaginidae) based on Geometric Morphomeyrics Analysis in the northern Persian Gulf, Bushehr Province

The aim of this study was to evaluate the efficiency of geometric morphometrics for describing the body shape of fish larvae, and identifying them to speciess. Species of sillaginid fishes (Perciformes: Sillaginidae) were chosen as the model group, as the larval stages in this family are particularly difficult to identify. 47 individuals collected from the central creeks of Bushehr province between June 2013 and April 2014 using bongo net. The individuals were first divided to three developmental stages, preflexion, flexion and postflexion. Then flexion and postflexion larvae were divided into three groups, depending on 34, probably 34 and 38 myomers. The larvae with 34 myomeres were identified as Sillago sihama. After counting myomers, 8 landmarks were digitized on pictures taken from left side of specimens. Data were analyzed using PCA and DFA after procrustes superimposition and data standardization. There are some meaningful shape differences between three groups (P<0.001), especially between 34 myomers group and other two groups. The preanal length in 34 myomers group was shorter than that of 38 and probably 34 myomers groups. The body height in 38 myomers group was higher than probably 34 myomers group. Therefore, geometric morphometrics is a promising tool for identifying fish larvae to species level.