الفهرس 
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Abstract
VI. English summary
The current study carried on seventy-five fish from the white grouper (Epinephelus aeneus) of the different five age-stages (fifteen fish from each age-stage). This study focused on the oropharyngeal cavity of the white grouper due to their high marketing value as this fish species had an excellent tasting value, rapid growth, and the high resistant to numerous fish diseases.
The current examination and anlayzed the data of the five different age-stages of the white grouper (Epinephelus aeneus) clearify that there were numerous characteristic features comined between the examined five age-stages that summerized in the Table 1-5. In other hand, there are some variations observed by the ultrastructure characterizations of the oral cavity teeth between the different examined five age-stages and between the roof and the floor of the same fish age that summerized in Table 6-8. The morphometric variations were illustrated in the charts 1-6.
The oral cavity of the different five age-stages of the white grouper (Epinephelus aeneus) fish was divided into two halves; upper and a lower jaw. The mandibular jaw was longer than maxillary jaw. The oropharyngeal cavity of the five different age-stages of the white grouper is provided an essential information to help the process of aquaculture of this fish species in the Egypt by providing data on the oral cavity and its related structures of this fish that determine the type of the food particle that favorite to this fish.
The oral cavity of the Epinephelus aeneus in the different five age-stage opened anteriorly by a wide semilunar mouth with strong dentition and the longer mandibular jaw than the maxillary jaw and bounded rostrally by the upper and the lower lips.
The oral cavity of Epinephelus aeneus in the different five age-stages had a system of micro-ridges of different name; micro-lines on the dorsal lingual surface (two lateral spinated lingual lines) and roof of the pharyngeal cavity (two lateral pharyngeal lines), micro-tubercles on the dorsal lingual surface (the median lingual tubercle), the roof of the oropharyngeal cavity, but the micro-ridges appeared on the dorsal lingual surface, the roof and the floor of the oropharyngeal cavity, between the lip and the teeth (the median lingual ridge, the median palatine ridge, the upper and lower incisive ridge, the lower and upper molar ridge, the palatine ridge, the vomer ridge, the median sublingual ridge and the numerous ridges on the oral surface of the velum and lips in the 18cm fish). Meanwhile, there is a crest on the roof of the oropharyngeal cavity (the only one palatine crest in all examined fish ages except the 5cm age fish had a two-palatine crest).
The current observation of the micro-ridges system in the oral cavity of the white grouper (Epinephelus aeneus) in the different five age-stages may be illustrate the carnivorous behavior and the role of this micro-ridges system in catching of the taken food particles and prevent the escaping of these intake different food particles, the mechanical protection of the oral cavity mucosa from injuries by hard intake food particles, provided the channels for the mucous passage and increase the effective total surface in the digestion and absorption process.
The upper incisive ridge of the white grouper (Epinephelus aeneus) in the different five age-stages was the most clear ridge on the upper jaw than the lower incisive ridge. The longitudinal part of the upper incisive ridge divided the area of the incisive and canine teeth into two groups; right and left teeth area.
The first observation of the numerous characters on the transverse part of the upper incisive ridge in the different five age-stages that carried numerous microcrests of the different directions giving the appearnce of the quadrilateral cells and separted from the longitudinal part by a small shallow interridged groove. While, the longitudinal part of the upper incisive ridge appeared as longitudinal thick elevtaed projected ridge that projected ventrally inward the oral cavity and carried a numerous small microspines, while the wide base attached to the ventral surface of the upper jaw, then the longitudinal part was continous posteriorly on the oral surface of the upper velum.
The longitudinal part of the upper incisive ridge extended on the oral surface of the upper velum had variation between the examined age-stages of the white grouper (Epinephelus aeneus) as the following; at 5cm age fish appear as a slight rough line that not reach the posterior border of the upper velum, at the 8cm age fish the ridge reached to posterior border of the upper velum, and at 12cm, 15cm and 18cm age fish not reached to the posterior border but with different distance as described in the table 4. While, generally the longitudinal part if the lower incisive ridge not reached to the posterior border of the lower velum as described in the Table 7.
The upper and lower lip of the white grouper (Epinephelus aeneus) in the different five age-stages was hard in texture due to the presence of the numerous small lobulations with numerous microtubercles and microspines and the lip divided according to its position into; median anterior part and two lateral part, in addition to the anterior surface of the upper lip had a median fissure that divided the upper lip into two equal halves (right and left) in all age-stages except in the 5cm age fish.
The lower lip of the white grouper (Epinephelus aeneus) in the different five age-stages observed that not fissured but carried some taste buds type II and III, and characterized by the presence of a non-elevated median structure that located between the two dentaries with a high number of the filiform-like papillary structures.
The roof and floor of oropharyngeal of the white grouper (Epinephelus aeneus) in the different five age-stages was U-shaped in appearnce to correspond with the shape upper and lower jaw. The upper and lower jaw continuous rostrally with the lip and posteriorly with the velum
The palatine region of the white grouper (Epinephelus aeneus) in the different five age-stages was divided into two halves by the presence of the palatine teeth band and the vomer teeth band into; the peripheral horse-shoe appearance part and the diamond-shaped median center part, in which the wide triangular-shaped median palate separated from the peripheral part of the palatine region by the longitidnally arranged palatine crest carrying the palatine teeth band and the longitidnal palatine groove laterally and the vomer teeth band anteriorly. The palatine region of the white grouper (Epinephelus aeneus) in the different five age-stages had two types of teeth bands; two laterally situated palatine teeth band and a single anteriorly situated vomer teeth band.
The palatine region of the white grouper (Epinephelus aeneus) in the different five age-stages had numerous microridges of differnet names according to their shape in which there are; numerous microridges (median palatine ridge, paramedian palatine ridge, transvere ridge, vomer ridge, two transverse palatine ridge and palatine rdige), crest (two laterally situated palatine crest carring the palatine teeth band except the 5cm age fish carried four laterally situated palatine crest), process (vomer process), and microtbercles (distributed on the roof of the palate especially onn the median palatine ridge).
The upper and lower velum of the white grouper (Epinephelus aeneus) in the different five age-stages were a thin semilunar membrane in apppearnce that located at the inner boundary of the jaw and had two surfaces, two borders and two parts (two laterally sitated narrow parts and a single median wide part). The oral surface of the velum had a numerous slightly elevated fungiform papillae bearing taste buds type I especially at the middle part of the velum. The current observation of the white grouper (Epinephelus aeneus) observed that, the oral suarface of the lower velum of the 15cm and 18cm age fish had a characteristic transverse and longitidinal velvar ridges that not reported previously in any species.
The longitidnal part of the upper incisive ridge extended on the median part of the oral surface of the upper velum reached to the posterior border of the upper velum in 5cm and 8cm fish while not reached to the posterior border of the valve in the 12cm, 15cm and 18cm fish. While, the longitidinal part of the incisive ridge was small and shallow in appearance on the oral surface of the lower velum and not reach to the posterior border.
The median part of the ventral surface of the upper velum had a very small two rough area located just laterally on each side of the longitidinal part of the upper incisive ridge in 5cm and 8cm age fish, while become wide area with different directed ridges (transverse, longitudinal and oblique) in the 12cm fish but in the 15cm and 18cm fish appeared as two incisive area that carried different directed ridges (transverse, longitudinal and oblique).
The triangular shaped single unpaired vomer located anterior to the palate and carried the vomer teeth band. The vomer carried a little number of the taste buds III, while the few taste buds type II were located between the vomer teeth.
The elongated non-mobile and non-protrusible muscular tongue of the white grouper (Epinephelus aeneus) in the different five age-stages extended backword till the begining of the pharynx. The tongue had three parts; apex, body and root with two clear lateral border. The tongue not carried any taste buds. The lingual apex had a pointed apex in 5cm, 8cm, 12cm age fish, while had a rounded lingual apex in 15cm and 18cm age fish.
The dorsal lingual surface at 5cm age fish was smooth, except the presence of the two laterally situated lingual spinated thin lines on the dorsasl lingual surface, while in the rest four age stages carried numerous microtubercles, median lingual ridge and the two laterally situated lingual spinated thin lines. The median lingual ridges were absent in 5cm age fish, while in the rest four age stages carried a median lingual ridge with numerous microtubercles and microlines on it.
The roof of the oral cavity of the five age-stages of the white grouper had five teeth bands that described as the following; upper incisive teeth band, cannine teeth band, upper molar teeth band, vomer teeth band and palatine teeth band meanwhile, the oral cavity floor had only two teeth bands; lower incisive teeth band, lower molar teeth band with the complete absence of the canine, vomer, and palatine teeth.
The current study in white grouper (Epinephelus aeneus) of the five different age-stages reported that the presence of the characteristic feature of the proximal apex of the pointed curved teeth that had a cap-like arrowhead pointed structure that surrounded by a circular groove distally.
The upper and lower incisive teeth classified into three group; small, medium and large upper incisive teeth that arranged into three rows; rostral, medium and caudal rows, in which the rostral row usually contain the small straight upper incisive teeth and the medium row contain a mixture of the small curved and medium upper incisive teeth and may contain some large upper incisive teeth, while the caudal row mainly contain the curved large upper incisive teeth.
The canine teeth were observed on the upper jaw only and completely absent in the lower jaw. At the 5cm, 8cm, 12cm and 15cm fish age observed that the canine teeth were arranged in two group (anterior and posterior group) in which each group of the canine teeth contain two canine teeth and located at the lateral boundary of the incisive region while, at the 18cm age fish stage observed that the each group of the canine teeth contain four canine teeth that laterally located at each two teeth area, in which the four anteriorly situated canine teeth is the larger and the more curved teeth than the four caudally situated canine teeth and the current work classified the four anterior and four posterior canine teeth according to their length into; two short and two long anterior canine.
The vomer teeth of white grouper in five different age-stages take the pointed with arrowheads proximal apex directed toward the oral cavity that arranged in triangular manner in only one row of semicircular appearrance in the 5cm fish, while in the 8cm and 12cm fish the vomer teeth arranged in a triangular manner in two rows while, in 15cm and 18cm fish the vomer teeth were arranged in a triangular manner in more than two rows.
The palatine teeth began anteriorly as one row then arrnaged in two rows and terminnated by one row in the 5cm fish, while in the 8cm, 12cm, 15cm and 18cm fish the palatine teeth band began anteriorly as two rows then arrnaged in three rows and terminated posteriorly as two rows.
The current study in the examined white grouper (Epinephelus aeneus) fish of the five different age-stages reported that, there are a little number of taste buds type I, II, and III on the epithelium of the oropharyngeal cavity that distributed as the following; the epithelial protrussion located between the upper lip and the teeth had a little number of the taste buds type II and III, while the epithelial prortrussion of the lower lip and between the teeth was carried a little number of the taste buds type II.
The epihelial protrussion between the molar teeth had a little number of taste buds type II and III. The oral surface of the upper and lower velum had a high number of a slightly elevated fungiform papillae that had numerous taste buds type I. The vomer carried a little number of the taste buds III, while the few taste buds type II were located between the vomer teeth. The epitherlial covering of the two lateral area of the palatine region was characterized by the presence of numerous palatine ridges and little amount of the two types of the taste buds type II and III. The epithelium covering of the palate was characterized by the presence of the taste buds; type II and III. The palatine teeth charcterized also by the presence of little number of the taste buds type II and III.
The current study in the white grouper (Epinephelus aeneus) of the five different age-stages reported the presence of the mucous producing cells on oral surface of the palatine region of the upper jaw and the floor of the oral cavity in the area surrounding the tongue, while absent completely on the tongue, velum, and lips. In addition, our current study observed that the mucous-producing cells were surrounded by an elevated circular micro-ridges.
The floor of pharyngeal cavity in the examined white grouper (Epinephelus aeneus) fish of the five different age-stages formed from the epipharyngeal bone and had three ridges; two transverse pharyngeal ridges, a single paramedian pharyngeal ridge, in addition to a clear interbranchial septum (that located between the origin of the gills from the floor of pharyngeal cavity), its connection with the gills and there are two micro-lines named the two spinated pharyngeal lines.
The current study in the examined white grouper (Epinephelus aeneus) fish of the five different age-stages reported that, the four ridges on the roof of oropharyngeal cavity; the median longitudinal palatine ridge, the median longitudinal pharyngeal ridge and the two transverse pharyngeal ridges were meet at the central area.