Will the Real SpearFish Please Come Forward?

It is very seldom that I come across a marine identification crisis that stirs so much debate and discussion among experienced charter captains, old salty anglers, and scientists alike. Interestingly, a notable billfish encounter experienced by my crew of marlin hunters this August has done just that.

The Mystery Billfish:
Our offshore quest that steamy summer day was for billfish of the white or blue variety. So with Captain Steve Wray at the helm and a skilled crew of four of my fishing pals, we headed for marlin territory in the deep waters off Virginia and North Carolina. When the fish hit the bait, little expertise was required since there was no question it was there, as evidenced by the line screaming off the reel. The first thing I noticed was the absence of that introductory telltale jump announcing the fish’s identity as is typical for marlin once he detects he is hooked. Instead, the fish finned and zigzagged just below the surface, and occasionally threw his head out of the water, angrily shaking his bill in protest. With the sight of this, I declared the species of our billfish as a white marlin. Once afforded a closer look at our catch, although we were bustling about to get business done in order to return the fish safely to its home, I remember thinking that it was the strangest looking marlin I had ever seen. After the fish was revived and high-fives ensued, we considered our mission accomplished as we trolled on in search of more action, with little more discussion addressing the odd appearance or behavior of our white marlin of the hour.

It turns out that on that very day, and during the weeks surrounding our peculiar billfish extravaganza, other offshore boats and crews claimed to have boated multiple longbill spearfish mixed in with the marlin. With that coincidence, the emergence of an interesting and educational journey to identify the mystery billfish we encountered that day blossomed, and continues.

What Exactly is a Spearfish?
The Atlantic longbill spearfish is a beautiful silvery pelagic billfish very comparable to its close relative, the white marlin. Spearfish are considered to be the rarest of the billfish family, and can be found in the deep offshore waters in warmer tropical and subtropical climates. In the western North Atlantic, longbill spearfish occur from off our coast down to Venezuela, including the Gulf of Mexico, along with other pelagic fishes such as billfish and tuna. Currently, the largest longbill spearfish on record weighed in at 94 pounds, 12 ounces. Because these fish are usually a pleasant surprise, occurring as an incidental catch by anglers targeting other species, there is limited information or knowledge about spearfish or their behavior patterns.

Targeting spears as a game fish is unreliable due to sparse catches, but they are caught using the same lures, bait, tackle and methods as used while fishing for white marlin. These elusive fish seem to prefer smaller sized prey, and will tend to pick out the smaller of the lures and baits in a spread while trolling. Keep in mind that possessing a spearfish is prohibited by law, so safely return him the water as soon as possible if he visits your spread.

Why the Confusion?
Why in the world is there such difficulty distinguishing between the common white marlin and the rare Atlantic longbill spearfish? Surprisingly, this is no easy feat. The two fish, although completely different species of billfish are so similar in appearance that only slight variations, easily missed by even experienced anglers, differentiate the two types of fish. According to Captain Keith Fraser of Alltackle Charters who released a spearfish last year off the coast of Maryland, most anglers can’t tell the difference between the two fish, and he suspects that every year many spearfish are misidentified and registered as white marlin by mistake.

What are the Differences?
In the midst of all the hustle and excitement in the cockpit during a coveted billfish battle, along with all of the other necessities of a skillful release, the notation of mere and slight differences to identify the proper species of billfish could understandably prove to be a challenge. There are a few key differences between the spearfish and white marlin, which may prove helpful in discerning their true identities, especially in a rush.

Although a spearfish will generally crash a bait hard, don’t expect an aerobatic display of billfish calisthenics if hooked into a spearfish. Experienced spearfish captains seem to agree that these marlin-look-alikes put up a wimpy and short-lived battle at best, lending to your first clue that something is up. The most significant and most observable physical difference between these two deepwater dwellers is the shape, height and color of the dorsal fin spanning down the center of fish’s back. The prominent dorsal fin of the spearfish emanates a brilliant neon blue color, completely lacking in the typical spackling of dark spots among the dark blue or black background as is common to the entire marlin family. Also, the most forward and highest portion of the dorsal fin of a spearfish is generally more angled in appearance, while the white marlin has a more rounded fin. The remaining less tall segment of the dorsal fin of a white marlin only stands about 2-3 inches high as it runs down the length of the back, while the spearfish has a much different presentation in that the fin is taller, running close to 6 to 8 inches off their backs.

Another notable difference between the two fish is that of their general body coloring and body shape. The spearfish’s silvery core will appear to be “missing something” in that the vertical striping along the length of his body is usually absent or very slightly visible, while the marlin’s stripes are quite prominent and noticeable. Spearfish in general also tend to be a little smaller in size than the average white, and display a long, slender body type. These fish appear to be almost “skinny,” lacking the broader shoulders of a white marlin.

But, if all these features fail to help confirm the identity of your mystery billfish, here is the final distinction, which may dispel any further doubt: examine the billfish’s rear-end. Yep, that’s right. It seems that the spearfish’s vent is located much further forward of the fish’s anal fin than it’s near-twin imposter, the white marlin. Jon Lucy, a researcher at the Virginia Institute of Marine Science, suggests “The relative location of the vent is most likely the most telling physical attribute for quickly distinguishing the two species at the boat.” So if all else fails, bottoms up, and photos please!

The “Hatchet Marlin”
Now to confuse the issue even more, Dr. John Graves, a marine researcher at the Virginia Institute of Marine Science who is currently researching genetic variances among pelagic species, including billfish, suggests that the mystery fish may actually be a variety of billfish referred to as a “hatchet marlin.” According to Dr. Graves, the hatchet marlin has been confirmed in surprisingly large numbers in our local offshore waters, and may be easily confused with the white marlin and the spearfish. The problem is, scientists are not sure what the heck a “hatchet marlin” truly is, so it is currently a biological mystery. The appearance of these billfish is extremely similar to that of the white marlin, with a few variations. The main distinction between the two billfish is that the dorsal and anal fins of the hatchet marlin are squared off, and its pectoral fins are more pointed than the normal white marlin. In addition, the hatchet marlin tends to stay lit up even through its release. And of course, these fish are afforded no privacy either, with its vent placed a bit further forward than a white marlin’s, but not nearly as far forward as a spearfish’s rear-end anatomy. Dr. Graves is actively involved in the genetic research to categorize these fish as a possible separate species of billfish. He claims that with further genetic analysis, researchers hope to determine if the “hatchet marlin” is a completely separate billfish species, or rather a sub-species, variant or even a hybridization of the white marlin or the spearfish. Currently, the hatchet marlin is considered a variation of the white marlin.

When offshore anglers happen across a peculiar billfish catch, the researchers involved with the genetic analysis of billfish are more than thankful to receive a tissue sample to help unravel some of the billfish mystery. Dr. Graves states that he will provide a small vile for preservation by calling him at 804-684-7352. It is very easy to obtain a sample by simply snipping a small piece of a fin; this can be done with the fish in the water! Place the fin clip into a zip-loc and keep it on ice and then freeze it while awaiting the arrival of the vile. Try to record the pertinent information concerning your catch such as the date, time and location of your billfish encounter. Dr. Graves reminds us “Most important, get some photos and yes, even where the sun doesn’t usually shine!”

Educating offshore anglers and charter captains on the proper identification and thus credible reporting of the different billfish species will help researchers gain more accurate data on the behavior, location, and other imperative useful information on our treasured billfish populations in general.

For Charters with Captain Steve Wray (757-481-7517).
Special thanks for information and guidance provided by Dr. John Graves, Chair, Department of Fisheries Science, Virginia Institute of Marine Science of the College of William and Mary, and Jon Lucy (VA Sea Grant Advisory Services), researcher at the Virginia Institute of Marine Science of the College of William and Mary.

Additional thanks to Captain Keith Fraser of All Tackle Charters (888-810-7283), and Captain Vinnie La Sorsa of Good Fellas Charters (954-254-7700) for sharing of their spearfish knowledge and photos.

Also thank you to Diane Peebles, artist, for providing detailed illustrations, her artwork is available for purchase at dianepeebles.com.
Resources: National Marine Fisheries Service, Office of Sustainable Fisheries, Highly Migratory Species Management Division; Florida Fish and Wildlife Conservation Commission, Division of Marine Fisheries Management; Marlinnut.com.