Student worksheet: Bony fish anatomy - Brown stripe snapper ... - Free Printable

Based on the diagram provided, here are the labels for the blank lines pointing to the fish's anatomy. I have identified them by looking at their position and function on the fish.

Step-by-step Identification:

1. Top Fin (Dorsal Fin): The line pointing to the large fin on the top of the fish's back is labeling the dorsal fin. This helps the fish stay upright.
2. Bottom Fins (Anal and Pelvic Fins):
* There are two lines near the bottom rear.
* The line pointing to the single small fin located just in front of the tail (and behind the vent/anus) is the anal fin.
* The line pointing to the paired fins on the belly (underneath the gill area) are the pelvic fins.
3. Tail Fin (Caudal Fin): The line pointing to the main tail fin at the very end of the fish is labeling the caudal fin (or simply tail fin). This is used for propulsion.
4. Side Fin (Pectoral Fin): The line pointing to the fin on the side of the body, just behind the head/gills, is the pectoral fin.
5. Internal Organs:
* Swim Bladder: The large, empty-looking sac located in the middle of the body cavity (above the intestines) is the swim bladder. It helps the fish float.
* Liver: The large, dark reddish-brown organ located at the front of the belly (near the heart and pyloric caeca) is the liver.
* Stomach: The J-shaped organ connected to the esophagus and leading into the intestine is the stomach.
* Heart: The small red structure located low down, just behind the gills, is the heart.
* Gills: The feathery red structures inside the head cavity are the gills.
* Kidney: The dark strip running along the top of the body cavity, right under the spine, is the kidney.

Here is the completed list for the blanks on your worksheet:

External Features (Fins & Body):
* Top fin: dorsal fin
* Side fin: pectoral fin
* Belly fins: pelvic fins
* Rear bottom fin: anal fin
* Tail fin: caudal fin (or tail fin)
* Lateral line (the faint line running horizontally along the side): lateral line

Internal Organs:
* Large sac in the middle: swim bladder
* Dark strip under the spine: kidney
* Large brown organ in front: liver
* Red pump near gills: heart
* Feathery parts in head: gills
* Sac after the stomach: stomach

*(Note: Since this is a specific species worksheet for the "Brown-stripe snapper", you would typically fill in the Common Name as Brown-stripe snapper and the Scientific Name as *Lutjanus vitta* if required by your teacher, though these aren't strictly anatomical labels.)*

Final Answer:
Top to Bottom, Left to Right Labeling Guide:

1. Line pointing to the top fin: dorsal fin
2. Line pointing to the tail fin: caudal fin
3. Line pointing to the rear bottom fin: anal fin
4. Line pointing to the side fin: pectoral fin
5. Line pointing to the belly fins: pelvic fins
6. Line pointing to the horizontal line on the skin: lateral line
7. Line pointing to the large internal sac: swim bladder
8. Line pointing to the dark strip under the spine: kidney
9. Line pointing to the large brown organ: liver
10. Line pointing to the red organ near gills: heart
11. Line pointing to the feathery structures: gills
12. Line pointing to the digestive sac: stomach