The regional distribution and relative frequency of neurohormonal peptides-producing cells were demonstrated in the gastrointestinal (GI) tract of the Korean aucha perch Coreoperca herzi, using 10 types of specific antisera raised against mammalian regulatory peptides. The GI tract was divided into four portions: stomach, gastro-intestinal junction, and small and large intestine. Most of the immunoreactive (IR) cells were in the mucosal epithelium and they were generally spindle shaped with a long cytoplasmic process. In addition, ovoid cells were found in the gastric regions. Serotonin-, somatostatin-, glucagon-, cholecystokinin-8 (CCK-8)-and pancreatic polypeptide (PP)-IR cells were observed with various relative frequencies. No chromogranin A-, secretin-, vasoactive intestinal peptide-, substance P-or bombesin-IR cells, however, were found. Serotonin-IR cells occurred throughout the GI tract and were the most numerous. Somatostatin-IR cells were restricted to the stomach and gastro-intestinal junction in numerous and moderate frequencies, respectively, but small numbers of glucagon-IR cells were restricted to the small intestine. Numerous CCK-8-IR cells were found in the small intestine but variable numbers of PP-IR cells occurred throughout the GI tract except for the large intestine. In general the distribution and relative frequency of these IR cells correspond well to previous reports in teleosts but there are some difference in this species. # 2004 The Fisheries Society of the British Isles

The regional distribution and relative frequency of endocrine cells in the alimentary tract of the red-eared slider, Trachemys scripta elegans, were investigated by immunohistochemical methods using 10 antisera. Most of the immunoreactive cells in the intestine were spherical or spindle-like in shape (open-type cells), while round cells (closed-type cells) were occasionally found in the stomach. These immunoreactive cells were located in the basal portion of the intestine, including the oesophagus, and in the gastric glands of the stomach. Cg A-immunoreactive cells were restricted to the pylorus and duodenum and were few in number. Serotonin-immunoreactive cells, which were most commonly found in the pylorus, were found in the epithelia throughout the alimentary tract at various frequencies. Gastrin-immunoreactive cells were found in the pylorus, duodenum and jejunum at moderate, low and very low frequencies, respectively. Somatostatin-immunoreactive cells were found throughout the alimentary tract except for the rectum, at various frequencies. Glucagon-immunoreactive cells were detected in the fundus, pylorus, jejunum and ileum at low or very low frequencies. CCK-8-immunoreactive cells were found in the pylorus, fundus and duodenum at very low, low and moderate frequencies, respectively. Bombesin-immunoreactive cells were restricted to the fundus and pylorus at low frequencies. No secretin-, BPP- or VIP-immunoreactive cells were found in this study.