Effects of First Feeding Regime on Gene Expression and Enzyme Activity in Pikeperch (Sander lucioperca) Larvae

The present study investigates the effects of different feeding regimes with rotifers ( Brachionus plicatilis ) and Artemia salina on gene expression digestive enzymes in pikeperch Sander lucioperca larvae at 17 days post-hatch (DPH) over a period 13 days. Five experimental protocols were performed four replicates. At 4 DPH, (total length= 5.62 ± 0.03 mm, body weight = 0.66 0.16 mg) divided into five groups (2-L tanks) initial density 100 per liter. Light intensity water surface was 90-100 lux photoperiod set 13L: 11D (07:00 to 20:00 h). Water temperature, pH, dissolved oxygen (DO) measured before each values 17.8 0.17°C, 7.3 0.04 88.5 2.53%. fish 5 (DPH), initially fed for 3 from 8 DPH rotifers/ time periods as follows: (A) only rotifers; (B) 8–13 rotifers/14–17 ; (C) 8–10 rotifers/11–17 (D) (E) combination Artemia. Frozen paste algae added larval tanks twice day (2 x 300,000 cells/mL). Rotifers provided live feed three times residual counts prior feeding. Feeding densities steadily increased based counts, genes related intestinal development maturation aminopeptidase N, anpep; leucine 3, lap3; intestinal-type alkaline phosphatase, alpi ), together key pancreatic proenzymes trypsinogen 1, try1; chymotrypsinogen b, ctrb; carboxyl ester lipase precursor, cel; phospholipase a2, pla2g1b; alpha amylase, amy2a assessed. Additionally, activity six (trypsin, lipase, amino peptidase, chymotrypsin) determined. highest two intestine anpep observed (Group E). amy2a, ctrb, pla2g1b, try1 significantly lower until 14 replaced by afterwards B). specific brush border membrane (alkaline phosphatase N) diet E), indicating more efficient functionality structures. till A) (38 4.07%) followed B) (36 5.25%) showed P <0.05) survival rates than other (54-67%). group growth rate (SGR) groups, SGR found after rotifer standard length (8.32 0.48 mm) obtained combined Combination E) could be considered appropriate first compared later introduction , indicated higher activities enzymes. Our findings provide new insight effect temporal sequence larvae.