THEILACKER and VVATANABE: NUTRITIONAL STATUS OF NORTHERN ANCHOVY 



larval northern anchovy; it extends from behind 

 a constriction at the pylorus to another constric- 

 tion at the beginning of the hindgnt (Fig. 1). We 

 measured the cell heights under a light micro- 

 scope using the histological preparations. 

 Epithelial cells of the midgut tend to decrease in 

 height from the anterior part to the posterior 

 end. We chose the midpart of the midgut (from 

 2/5 to 3/5 of the entire length) as the measure- 

 ment site. The area is easily located in histolog- 

 ical sections that are cut parallel to the median 

 plane. The dorsal and ventral rows of midgut 

 cells appeared in these sections. We measured 

 the cells of the ventral row that were larger than 



the dorsal row, probably because of greater ab- 

 sorptive activity. We selected a section having 

 four to six neighboring cells in which the nuclei, 

 brush border, and cell base were clearly defined; 

 brush border may be indistinct in larvae of poor 

 condition. Measurements were taken from the 

 luminal surface of the brush border to the cell 

 base delimited by a basement membrane, using a 

 micrometer attached to an eye lens. Usually, in 

 sagittal sections, the cell heights are not so var- 

 ied within the middle part of the midgut. If, 

 however, there were slight differences between 

 cells due to a slight angle of the section, we took 

 an average of several measurements. 



midgut cell height (mght) statistics for fed northern anchovy by diet and age. 



Age 

 (days) 



Starved 1 d/fed 



Starved 2 d/fed 



Growth 



Midgut 



Growth 



[yiidgut 



SL' X 



mm 



SD 



SL' X 

 mm 



mght^ X 

 fjim 



SL' X 

 n mm 



SD 



SL' X mght^ x 

 mm n,m 



4 

 5 

 6 



7 

 8 

 9 

 10 

 11 

 12 

 13 

 14 

 17 

 19 



33 

 47 

 61 

 23 

 49 

 46 

 55 

 71 

 47 

 61 

 121 

 26 



STARVED 



3,55 

 3.59 

 3.46 

 3.81 

 4.34 

 4,90 

 5.09 

 5.56 

 5.86 

 6.32 

 6.84 

 7.19 



0.20 

 0.37 

 0.23 

 0.31 

 0.46 

 0.39 

 0.56 

 0.47 

 0.45 

 0.62 

 0.86 

 0.95 



12 

 15 

 11 

 10 

 11 

 10 



3.95 

 3.60 

 3.45 

 3.77 

 4.79 

 4.80 



14.27 

 15.83 

 14.89 

 16.00 

 19.32 

 18.63 



Total n 640 



69 



27 

 33 

 31 

 18 

 38 

 41 

 28 

 27 

 46 

 33 

 39 



361 



3.58 

 3.39 

 3.58 

 4.07 

 4.25 

 4.58 

 4.95 

 4.99 

 5.63 

 6.25 

 6.65 



STARVED 



STARVED 



0.22 

 0.18 

 0.21 

 0.21 

 0.32 

 0.31 

 0.39 

 0.41 

 0.45 

 0.73 

 0.93 



18 

 10 

 17 

 10 

 11 

 10 



3.57 

 3.35 

 3.60 

 4.02 

 4.19 

 4.60 



13.47 

 11.88 

 12.21 

 14.63 

 14.77 

 15.63 



76 



Starved 4 d fed 



8 



9 

 10 

 11 

 12 

 13 

 14 

 17 

 19 

 24 

 Total n 



19 3.40 0.19 



14 3.58 0.22 



6 3.66 0.12 



10 3.44 

 6 3.59 

 6 3.66 



10.51 



10.00 



8.13 



39 



22 



459 



