Identification, localization and morphology of APUD cells in gastroenteropancreatic system of stomach-containing teleosts

Table 2 APUD cells types and distribution feature and density in GEP system of 8 kinds of stomach-containing teleosts

Fish species	GAS	SOM	5-HT	GLU	CAL	GH	NF	INS
Northern	3 +++/+		5 +++/	ND	2 +/		1-6 ND	1-6ND
snakehead	4 +/				3 ++++/
(C.argus)					4 +++/
Ricefield eel	1 +++/+	1 +++/+	4 +++/	ND	1 ++++/		4/++	4/+
(M. albus)		3 +++/++			3 +/
					4 +/
Yellow catfish	3/++	3/++++	3 ++/	7 +++/	1 +/		3 ++++/	2/++
(P. fulvidraco)		4/++++	5 ++/		2 +/			4/+
		5/++			3 ++/
					4 +++/
					5 +/
Mandarinfish			3 +++/++			7 +++/	1-6 ND	1-6 ND
(S. chuatsi)		2 +++/++	5 ++/	7 +++/				7 +++/
		4 ++/++	6 ++
Largemouth			3 +/	7 ++++/	7 +++/		1-6 ND	1-6 ND
Bass			4 +/
(M.salmoides)			5 +++/
Oriental		7 +++/	3 ++/	7 ++++/	2 +/	7 ++++/+	1-6ND	1-6ND
Sheatfish			4 ++/		3/++			7 ++/
(S. asotus)			5 ++++/		4/++
					5 +++/
					7 +++/
Freshwater		4 +/	2 +/+	7 ++++/	1 +/		1-7ND	1-7ND
Pomfret		7 ++/	3 ++/+
(C. brachypomum)			4 +++/+
			5 +/
Nile tilapia		3 +++/	2 +++/+	7 ++++/			1-7ND	1-7ND
(T. nilotica)		4 ++/	3 ++/+
		5 +/	4 ++/+
		7 ++/	5 +/

Notes: 1 = esophageal epithelium/esophageal gland; 2 = cardiace pithelium/cardiac gland; 3 = gastric epithelium/fundus gland; 4 = pyloric epithe lium/pyloric gland; 5 = intestinal epithelium/intestinal gland; 6 = intermus cular nerve plexus of digestive tract; 7 = pancreatic island/pancreas; ++++ = above 30 IRE cells in one field 10 × 20; +++ = 20-29 cells; ++ = 10-19 cells; + = below 10 cells; No IRE cell was found if the parts of sample were not listed in table; ND = not detected.