FISHERY BULLETIN: VOL. 71. NO. 2 



Figure 13. — The mucosal epithelium 

 of the intestine (II) of cunner (X 

 1,000). am, ameobocyte; g, granu- 

 locyte; gl, granular layer; in, infra- 

 nuclear zone; nz, nuclear zone; p, 

 polymorpho-leucocyte; pr, parasite; 

 sb, subborder; sc, subcuticular zone; 

 sp, supranuclear zone. 



IP 



SC 





Sp 



y^ 



gl 



// 



* 



r 



% 



9 





<" am 



go 





5' 





* ft^ 



*i 



^■%> 



be 



V'f-r 



4^^^ 



m.^ 



I 



9 



« 





sp 





in I 



'^^ 



►7 



Figure 14. — The active absorption 

 epithelium of the posterior intestine 

 (III) of cunner (X 1,000). be, 

 basal cells; g, granulocyte; go, goblet 

 cell; in, infranuclear zone; 1, lympho- 

 cytelike cell; sb, striated border (sub- 

 border); sp, supranuclear zone; v, 

 vacuole. 



lively clear region and has a higher affinity 

 for eosin Y than the other regions. Cell mem- 

 branes are indistinguishable or indistinct re- 

 sulting in a homogeneous appearance. The 

 granular layer (Figures 12, 13) continues to 

 the supranuclear zone and is more basophilic 

 than other parts of the nonnuclear zones. In 

 well-fed sjiecimens, the resting cells have the 

 same appearance as in the starved ones. Numer- 

 ous unstained vacuoles are present in the sub- 

 border and the supranuclear zone of the active 

 cells of the absorptive epithelium (Figure 14). 

 In many cases, vacuoles also appeared in the 



infranuclear zone. The granular cytoplasm of 

 the active cells forms a strong basophilic net- 

 work around the vacuoles. 



The nuclei of absorptive cells are ellipsoidal 

 with abundant basophilic granulation and a 

 large centrally located nucleolus. The nuclei 

 are located at the middle or the basal third of 

 the columnar epithelium at the intestinal bulb 

 and then gradually move to the upper third of 

 the epithelium posteriorly. As a result, the 

 depth of the supranuclear zone decreases slightly 

 posteriorly. The nuclei of the developing ab- 

 sorptive cells, the goblet cells, and other non- 



574 



