Question: Bubble-net feeding is a unique and complex feeding behavior engaged in by what animal, that has a distinctive body shape, with long pectoral fins and a knobbly head?

Context paragraphs:
Asterolepis (fish): Asterolepis is an extinct genus of antiarch placoderms from the Devonian of North and South America and Europe.  They were heavily armored flat-headed benthic detritivores with distinctive jointed limb-like pectoral fins and hollow spine.  The armor plate gives the "Asterolepis" a box-like shape.  Its pectoral fins are also armored but the caudal and dorsal fin are not.  The first fossils were named by M. Eichwald in 1840 after noticing star-like markings on the fossils.

Iniopterygiformes: Iniopterygiformes ("Nape Wing Forms") is an extinct order of chimaera-like cartilaginous fish that lived from the Devonian to Carboniferous periods (345–280 million years ago).  Fossils of them have been found in Montana, Indiana, Illinois, and Nebraska.  The Iniopterygians are characterized by large pectoral fins, wing-like projections on their backs, mounted high on the body and denticulated bony plates on the head and jaws.  Iniopterygian sharks were small, and their average length was about 18 in .  The elongated pectoral fins had denticles along the leading edge which may have had a role in mating.  They are thought to have been able to move their pectorals in a vertical plane,”flying” through the water much like modern-day flying fish.

Fish fin: Fins are usually the most distinctive anatomical features of a fish.  They are composed of bony spines or rays protruding from the body with skin covering them and joining them together, either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles.  Their principal function is to help the fish swim.  Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping.  Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling.  Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lure prey, and triggerfish avoid predators by squeezing into coral crevices and using spines in their fins to lock themselves in place.

White-spotted puffer: The white-spotted puffer ("Arothron hispidus") is a medium to large-sized puffer fish, it can reach 50 cm length.  It is light grey in color, or greyish or yellowish, and clearly covered with more or less regular white points, that become concentric contrasting white and dark grey lines that radiate around the eyes and pectoral fins.  The ventral part is white.  The "shoulder" (around the pectoral fins) is dark.  It also has concentric contrasting white and dark grey lines that radiate around the eyes and pectoral fins.

Callorhinchidae: The Callorhinchidae (sometimes spelled "Callorhynchidae"), or plough-nose chimaeras, are a family of marine fish containing one genus, Callorhinchus.  They are similar in form and habits to other chimaeras, but are distinguished by the presence of an elongated, flexible, fleshy snout, with a vague resemblance to a ploughshare.  The snout is used to probe the sea bottom in search of the invertebrates and small fishes on which it preys.  The remainder of the body is flat and compressed, often described as elongated.  The mouth is just under this snout and the eyes are located high on top of the head.  The usual color is black or brown, and, often a mixture between the two.  Phylogenetically, they are the oldest group of living jawed Chondrichthyes.  They possess the same cartilaginous skeleton seen in sharks but are considered holocephali to distinguish them from the shark and ray categorization.  Because of this, they provide a useful research organism for studying the early development of the jawed characteristic.  Among the Chondrichthyes genome, "Callorhinchus" has the smallest genome.  Because of this, it has been proposed to be used for entire genome sequencing to represent the cartilaginous fish class.  They are considered to resemble a cross between a shark and a ray or skate, but can be distinguished from sharks because they possess an operculum over their gill slits.  Additionally, their skin is smooth, not covered in tough scales, characteristic of the shark.  While the shark's jaw is loosely attached to the skull, the Callorhinchidae family differ in that their jaws are fused to their skulls.  Many classify the Callorhinchidae as a chimeric species due to their shared characteristics of both the sharks and rays.  They are found in muddy and sandy substrates of the ocean bottom, where they filter feed, with small shellfish making up the bulk of their diet.  They have broad flat teeth that have adapted for this type of eating habit, two pair that reside in the upper jaw and one pair in the lower jaw.  In addition to its utilization for feeding, the trunk of the Callorhinchus fish can sense movement and electric fields, allowing them to locate their prey.  They possess large pectoral fins, believed to aid in moving swiftly through the water.  They also have two dorsal fins spaced widely apart, which help identify the species in the open ocean.

Ogcocephalus radiatus: Ogcocephalus radiatus or the polka-dot batfish is an arrow-shaped fish in the Ogcocephalidae family with an elongated thin tail.  It is dorso-ventrally flattened with round pectoral fins that sit flat on the bottom of the sea floor.  It uses its pectoral fins and pelvic fins to "walk" along the bottom in a side-to-side shuffling motion.

Hirundichthys: Hirundichthys is a genus of flying fish.  Body elongate, moderately thick, flattened ventrally.  Pectoral branch of lateral line absent.  Upper jaw not protrusible.  Dorsal fin with less or equal (rarely with one more) rays than anal fin; dorsal fin low, anterior rays the longest, pectoral fins strikingly long, reaching to or almost to caudal fin base; pelvic fins long, reaching beyond anal fin origin, their insertion closer to anal fin origin than to pectoral fin insertion.

Humpback whale: The humpback whale ("Megaptera novaeangliae") is a species of baleen whale.  One of the larger rorqual species, adults range in length from 12 - and weigh about 36000 kg .  The humpback has a distinctive body shape, with long pectoral fins and a knobbly head.  It is known for breaching and other distinctive surface behaviors, making it popular with whale watchers.  Males produce a complex song lasting 10 to 20 minutes, which they repeat for hours at a time.  Its purpose is not clear, though it may have a role in mating.

Bubble net feeding: Bubble-net feeding is a unique and complex feeding behavior engaged in by Humpback whales (Megaptera novaeangliae) and Bryde's whales in Gulf of Tosa (), Japan.  It is one of the few surface feeding behaviors that humpback whales are known to engage in.  This type of feeding is often done in groups.  The group size can range from a minimum of two or three whales participating and up to sixty at one time.  Whales can also perform a similar method of surface feeding called lunge feeding but is done solo.

Prionotus evolans: The striped searobin (Prionotus evolans) is a fish belonging to the genus "Prionotus".  It was first described by Carolus Linnaeus in 1766.  It resembles the northern searobin, but differs in having a larger head, larger mouth, and longer pectoral fins.  In the species, the pectoral fins reach near the rear third of the second dorsal fin.  The tail is more square in the striped searobin, and the free pectoral rays taper toward their tips.  These filaments are banded in the striped searobin.  As the name implies, the striped searobin has a conspicuous narrow reddish-brown stripe along the side below the lateral line.  There is only one dark bar crossing the pectoral fin and usually it is so diffuse as to be a mere darkening of the center of the fin rather than a definite pattern.  It occurs from Florida to the Gulf of Maine, but it is rare north of Cape Cod.

Supporting paragraphs: Bubble net feeding Humpback whale
Answer: Humpback whale