Fig 1.
Changes in α- amylase activity (nmol glucose liberated min-1 mg protein-1) along the length of the Pacific hagfish alimentary canal and with respect to feeding status.
Activity was measured in both fasted (white bars) and fed (black bars) hagfish in five locations along the alimentary canal (B—buccal cavity, PCD—pharyngocutaneous duct, Ant HG—anterior hindgut, Mid HG—mid hindgut, Post HG—posterior hindgut). Bars represent means + s.e.m. of 5–8 hagfish. A Kruskal-Wallis analysis determined that there were significant differences between the anterior and posterior segments of the tract, thus a 2-way ANOVA to determine effect of feeding and location was conducted in the hindgut only (right of the dotted line). Asterisks (*) denote significant differences with significance accepted at α = 0.05.
Fig 2.
Maltase activity (nmol glucose liberated min-1 mg protein-1) does not change with feeding or location in the Pacific hagfish alimentary canal.
Activity was measured in both fasted (white bars) and fed (black bars) hagfish in five locations down the alimentary canal (B—buccal cavity, PCD—pharyngocutaneous duct, Ant HG—anterior hindgut, Mid HG—mid hindgut, Post HG—posterior hindgut). Bars represent means + s.e.m. of 4–7 preparations. A 2-way ANOVA of the entire tract determined there were no significant effects of feeding or location (α = 0.05).
Fig 3.
Lipase activity (μmol p-nitrophenol min-1 mg protein-1) is dependent upon location within the alimentary canal and significantly decreases post-feeding in the anterior segment.
Activity was measured in both fasted (white bars) and fed (black bars) hagfish in five locations down the alimentary canal (B—buccal cavity, PCD—pharyngocutaneous duct, Ant HG—anterior hindgut, Mid HG—mid hindgut, Post HG—posterior hindgut). Bars represent means + s.e.m. of 5–11 hagfish. Letters denote significant differences between locations as determined by a Kruskal-Wallis (α = 0.05) comparing anterior vs. posterior segments (separated by the dotted line), whereas asterisks (*) denote difference in feeding state as determined using a Mann Whitney Rank Sum Test (α = 0.05) within a segment.
Fig 4.
The trypsin activity (nmol p-nitroaniline produced min-1 mg protein-1) along the entirety of the Pacific hagfish hindgut does not change with feeding status.
Activity was measured in both fasted (white bars) and fed (black bars) hagfish in five locations down the alimentary canal (B—buccal cavity, PCD—pharyngocutaneous duct, Ant HG—anterior hindgut, Mid HG—mid hindgut, Post HG—posterior hindgut). Bars represent means + s.e.m. of 3–8 hagfish. BDL = below the detectable limits of the assay. A Kruskal-Wallis analysis revealed significant differences between the anterior and posterior segments of the tract, thus a 2-way ANOVA to determine effect of feeding and location was conducted in the hindgut only (right of the dotted line). Significance was accepted at α = 0.05.
Fig 5.
The activity of aminopeptidase (nmol p-nitroaniline produced min-1 mg protein-1) varies with location along the Pacific hagfish alimentary canal.
Activity was measured in both fasted (white bars) and fed (black bars) hagfish in five locations down the alimentary canal (B—buccal cavity, PCD—pharyngocutaneous duct, Ant HG—anterior hindgut, Mid HG—mid hindgut, Post HG—posterior hindgut). Bars represent means + s.e.m. of 5–12 hagfish. A Kruskal-Wallis determined that there were significant differences in activity between different locations, with differences indicated by different letters. Significance was accepted at α = 0.05.
Fig 6.
Feeding alters alkaline phosphatase activity (μmol p-nitrophenol produced min-1 mg protein-1) within the entire hagfish hindgut.
Activity was measured in both fasted (white bars) and fed (black bars) hagfish in five locations down the alimentary canal (B—buccal cavity, PCD—pharyngocutaneous duct, Ant HG—anterior hindgut, Mid HG—mid hindgut, Post HG—posterior hindgut). Bars represent means + s.e.m. of 6–12 preparations. No activity was detected in the anterior portion of the alimentary canal (BDL = below detectable limits). Therefore, a 2-way ANOVA was conducted for the hindgut regions alone (right of the dotted line) with significance accepted at α = 0.05. Asterisks (*) denote significant differences between feeding states.
Table 1.
Summary table depicting statistical relationships for the localization of α- amylase, maltase, lipase, trypsin, aminopeptidase, and alkaline phosphatase tissue activities in the Pacific hagfish alimentary canal.
Table 2.
Summary table of the effect of feeding on α- amylase, maltase, lipase, trypsin, aminopeptidase, and alkaline phosphatase tissue activities in the Pacific hagfish alimentary canal.