Abstract: In a method for automatically gutting fish of the catfish species, the belly cavity is opened around the anal orifice either before or after opening the gills by severing the gullet and opening the blood stream, and the contents of the belly cavity are removed by pushing these from one of the openings of the cavity out of the other. In a machine for carrying out this method, the fish are conveyed sideways by a recessed conveyor. The belly cavity is opened in the vicinity of the anus by separating away the cartilaginous plate carrying the ventral fins. The contents of the ventral cavity are removed by a rotary body rotating synchronously with the conveyor and having tools successively arranged in a cantilevered helix around its circumference which comprise a clearing tool with scraping segments, a brush tool, a high-pressure spray device and a cutting tool for slitting open the belly cavity along its length.

Abstract: A method for deboning fish is performed by means of an apparatus in which the fish rumps, with their head end leading, pass tools which initially cut free the belly spokes and ribs, the cutting free of the latter occurring up to the back spokes. These back spokes are then extracted from the back portion of the fish rump by downwardly displacing the vertebral column from the fish path, guide faces having scraping edges being guided in the rib cuts and extending up to the flanks of the back spokes, so that the extracting of the same is supported by scraping-off the meat from the back spokes. A splitting of the fish rump in the plane of the removed back spokes produces a double fillet when the cutting depth of the corresponding severing knife is limited up to the region of the tips of the belly spokes, whereas the gaining of individual fillets of maximum yield is possible by removal of the back fin strip together with the fin holders.

Abstract: The invention concerns a device for the automatic supplying of fish uniformly aligned with respect to their belly-back position to fish processing machines, which device comprises a belly-back aligning section, from which the fish is delivered to a processing machine in a timed manner. It is the object of the present invention to universalize the scope of use of known belly-back aligning sections in order to enable the handling of the great percentage of damaged fish which occurs due to set or drift net fishing. The increased danger of blocking of such aligning sections by damaged fish is avoided according to the invention in that the passage for the fish through the aligning section is opened by force shortly before the arrival of the next fish, respectively.

Abstract: A device for aligning fish to be handled in fish-processing machines is shown. The object of the invention is to lead fish, especially those with approximately circular cross-section to the processing tools so exactly that the processing can be carried out most economically, i.e. with a high yield without any danger of undesirable parts, e.g. the skeleton, remaining in the product to be used. The device according to the invention handles fish whose abdominal cavity is opened. The device comprises, in a known manner, a saddlelike guide element which supports the fish in its abdominal cavity, conveying means which engage the flanks of the fish being arranged on both sides of the guide element. A support surface which is formed with a concave cross-section carries knives extending into the fish path and lying flush with the support edges.