FISHERY BULLETIN: VOL. 71, NO. 2 



stratum compactum into the basement mem- 

 brane. 



Granulocytes in the submocosa of cunner 

 can migrate to both the mucosa and the muscu- 

 laris. According to Bolton (1933), basophilic 

 granule cells occur in vast number in con- 

 nective tissue throughout the gut of salmonid 

 fishes. He suggested that they were histogenous 

 cells developed from mesenchymal cells. Al- 

 Hussaini (1949b) mentioned that two types 

 of granulocytes also occurred in the intestine 

 of a variety of fishes; some stained blue with 

 Giemsa stain {Trlgla hirmido and Salmo trutta), 

 and others stained red with Giemsa (Scai'us 

 sordidus, Riitilus rutilus, Gobio gobio, Atherina 

 forskali, Cijprinns carpio, Crenilabruf! melops, 

 and MiiUoides ai(rifla»inia). Bullock (1963, 

 1967) stated that the granulocytes had varying 

 results in staining reaction according to the 

 different pH value of the stain, which was also 

 true in this study. Large granulocytes, densely 

 packed with granules which appear purplish 

 with Giemsa stain, were abundant in the mucosa 

 of cunner (Figure 14); smaller granulocytes 

 were present which have smaller red staining 

 granules in Giemsa (Figure 18). In addition, 

 a type of granulocyte was observed in which 

 the granules were condensed against the 

 nucleus (Figure 13). Bullock (1963) found cells 

 intermediate between granulocytes and globule 

 leucocytes in salmonids but not in Gambusia 

 affinis (Bullock, 1967). This intermediate type 

 cell was found in various levels of the epi- 

 thelium and submucosa of cunner intestine. 

 No precise cytochemical demonstration of the 

 possible relationships between granulocytes and 

 leucocytes was obtained in this study. The 

 wandering nature of the granulocytes did not 

 seem to correspond in any way with the food 

 contents in the intestine of the cunner. Aggre- 

 gations of granulocytes occurred in the sub- 

 mucosa of the bile duct, rectal valve, and anal 

 papillae of the cunner (Figures 16, 19, 20). 

 Granulocytes similar to those in the intestine 

 were also very abundant in the pancreas and 

 kidney. The function of granulocytes may 

 differ from species to species (Al-Hussaini, 

 1949b). The fine granules of the granulocytes 

 were stained with PAS in many specimens of 

 cunner. No evidence that granulocytes help 



in the absorption and transportation of di- 

 gested foods was found in cunner as reported 

 for other teleosts (Al-Hussaini, 1949b; Mohsin, 

 1962). Special aggregations of other types of 

 wandering cells such as: polymorphonuclear 

 leucocytes, lymphocytes, and amoebocytes were 

 not found. The presence of amoebocytes (Figure 

 13) with large vacuoles and a large nucleus 

 as observed in this study does not appear to 

 have been previously recorded. 



The muscularis of the esophageal-intestinal 

 valve (Figure 10) and rectal valve (Figure 19) 

 are formed of circular muscles. Gohar and Latif 

 (1959, 1961) mentioned only one layer of 

 muscle fibers in both the esophageal-intestinal 

 valve and the rectal valve of the labrid Julis 

 aygnla. This is true in the esophageal-intestinal 

 valve of the cunner, but in the rectal valve 

 of the cunner, the circular muscle layer is 

 folded and the two folds are separated by 

 fibrous connective tissue. Al-Hussaini (1947a, 

 1947b) indicated two separate muscle layers 

 in the ileo-rectal valve of the stomachless 

 Atherina forskali, and Western (1969) described 

 the same arrangement in Cottus gobio. It 

 would appear that a more careful analysis of 

 the intestinal-rectal (ileo-rectal) valve is 

 required. 



The differentiation of duodenum and ileum 

 reported to occur in stomachless labrids (Gohar 

 and Latif, 1961) was not found in the intestine 

 of the cunner. Histological differentiation of 

 the intestine was not mentioned by Curry 

 (1939), Al-Hussaini (1947b). Khanna (1961), 

 nor Bullock (1967) in other stomachless fishes. 

 Thickening of the circular muscle layer at the 

 anterior end of the rectum in cunner was similar 

 to that in other species of stomachless fishes 

 (Dawes, 1929; Al-Hussaini, 1947a, 1947b; 

 Khanna, 1961; Gohar and Latif, 1961; Mohsin, 

 1962; Bullock, 1967). However, the additional 

 thin layer of longitudinal muscle fibers present 

 inside the muscularis in the rectum of the 

 cunner was not reported by these investigators. 



Al-Hussaini (1949b) reported that alkaline 

 phosphatase was most abundant in the free 

 border of the absorptive cell of three species 

 of stomachless minnows — Cypnnus carpio, 

 Gobio gobio, and Rutilnt^ ri(tili(s. Similar re- 

 sults were found along the free border of the 



582 



