Tag Archives: Jacks

Predators

Blue Goatfishes and other fish hunt fro prey in the waters off Hawaii

It’s not unusual to see this kind of gang activity while snorkeling, and what they’re doing is hunting. Their prey is small fish that take sanctuary in coral heads and among the rocks.

This bunch of hunters is dominated by Blue Goatfishes, easily identified by their blue bodies and yellow saddle at the base of the tail. There’s also a Bluefin Trevally and Pacific Trumpetfish toward the bottom of the photo and, near the top of the photo, a Peacock Grouper with a Whitemouth Moray Eel curling below it.

Eels are popular members of these hunting parties because they can wriggle into the smallest spaces, flushing out prey. The goatfishes perform similar work using long, white barbels below the chin to probe small spaces in the hopes of disturbing a meal. Other fish tag along hoping to be beneficiaries of this work by being the first to snag any victims that get flushed out.

Threadfin Jack juvenile

A juvenile threadfin jack in the waters off Hawaii
A juvenile threadfin jack in the waters off Hawaii

This month’s Becky’s Squares challenge theme is ‘Odd.’ (See more responses here.) I have resisted the temptation to post 28 selfies, which will be a relief to everyone, including me. Instead, I start with a favorite fish of mine, the odd-looking Threadfin Jack juvenile.

The key word here is ‘juvenile,’ because when Threadfin Jacks mature, they end up looking like creatures that could provide security at a Beyoncé concert. But as juveniles, they sport a little diamond body, silvery with black bars, and an extravagant array of trailing filaments. This appearance is intended to mimic jellyfish, which was my assumption when I first saw one.

I used to see these regularly, but in the last couple of years I’ve only seen one pair, and that only for a fleeting moment. Not sure if that’s to do with changing conditions or that I’m missing them in the murkier water that prevails these days.

A look back at 2021

A Hawaiian monk seal resting
January: Hiwahiwa, a male Hawaiian Monk Seal born in 2020, rests at Upolu. Haven’t seen any monk seals since this encounter. (Link)

This week’s Sunday Stills challenge theme is ‘2021 in Your Rear-View Mirror.’ See more responses here. I’ve gone with a favorite photo from each month of 2021, with a caption and link to the post the photo first appeared in.

Wainanali’i lagoon at Kiholo, Hawaii at Kiholo, Hawaii
February: I love hiking at Kiholo Bay. There’s plenty to see and shady spots to rest awhile. (Link)
Spinner dolphins in the waters off the Big Island, Hawaii
March: Swimming with dolphins! Need I say more. (Link)
An I'iwi calls in a forest off Saddle Road, Hawaii
April: Another favorite hike, on Pu’u O’o Trail off Saddle Road, and an endemic I’iwi singing its heart out. (Link)
Close up of a coastal manta ray approaching
May: This inquisitive Manta Ray kept returning, probably wondering how something so clumsy-looking could survive in the water. (Link)
A Roseate Skimmer Dragonfly perched on a twig
June: I like seeing little creatures, such as this Roseate Skimmer Dragonfly, and I’m thrilled when the photos turn out. (Link)
Three palm trees in Hawaii
July: I like palm trees and word play so this was too tempting to pass up for Becky’s Tree Squares. (Link)
A school of mackerel scads, or Opelus being hunted by a rainbow runner off Hawaii
August: An instant in the water – a school of Mackeral Scads chased by a Rainbow Runner. They went by in a matter of seconds. (Link)
Red-masked parakeets at Kohanaiki Beach Park.
September: These Red-Masked Parakeets are not native, but they’re oh so tropical. (Link)
Early morning lights at the port of Kawaihae, Hawaii
October: When I have time, on my way to work, I stop at Kawaihae. I might see anything from a glorious sunrise, to a tiny crab on the beach, to these port lights. (Link)
The lava cone and lake at Kilauea Volcano in late 2021
November: Kilauea erupted again so I had to go look. The eruption is still going, but a little erratically these days. (Link)
A Green turtle, with a slender remora on its shell, checks out the photographer
December: A recent encounter and maybe my favorite Hawaiian Green Turtle photo. (Link)

Giant trevally

A giant trevally in the waters off Hawaii

A couple of days ago, I was snorkeling when I saw this enormous fish. I snapped a quick photo, fearful that the fish would quickly disappear. But it stuck around for a minute or two, passing back and forth in front of me, before sliding away into deeper water.

I knew it was a jack, but not one I’d seen before. When I got home, I dove into my fish book and figured out this was a giant trevally. According to my fish book, the giant trevally is the largest of the jack family. The biggest recorded catch is one that weighed 191 pounds. That would be heavier than me! That’s a tad worrisome because my fish book also notes that these curious and fearless fish ‘have been known to grab and rip away divers’ bright snorkel tips and colorful fins.’

This one was smaller than that, probably somewhere between three and four feet long, but comfortably the largest jack I’ve ever seen and probably the largest fish I’ve seen of any kind other than rays and sharks.

Bluefin trevally

A bluefin trevally in the water off the coast of the Big Island of Hawaii

I was getting close to the ladder where I get out after a swim, when two large bluefin trevallies went by. One swam off, but the other one turned around and to check me out and I snapped this one photo in murky water.

I was happy how it cleaned up and how it caught the fish’s curiosity and it’s sparkling blue markings.

Posted in response to Becky’s October Squares challenge theme of ‘Past Squares – Blue.’ See more responses here.

Leatherbacks

Leatherbacks off the coast of Hawaii

Leatherbacks are members of the Jack family and are most often seen singly or in pairs. I see them quite often and always try to get a photo of them and almost always fail. That’s because they have a tendency to surge upwards to feed and then zip back down.

On this occasion, a group of a dozen or more leatherbacks went by in the company of several bluefin trevallies and other fish. As usual, they were traveling at speed, but the numbers meant I had a better opportunity to get this photo.

Rainbow runner chasing a mackerel scad school

A school of mackerel scads, or Opelus off Hawaii

On a recent swim, I was turning to head for home when I saw this large school of fish rocketing towards me. As they zipped by I snapped the top photo. I could see they were mackerel scads, known in Hawaii as Opelu.

The reason for their haste also became clear as the last of them went by. The bottom photo shows a rainbow runner hot on their tails. Both fish are members of the jack family, but it’s a family that doesn’t get along. Mackerel scads are a favorite food of rainbow runners.

In a matter of moments, the fish disappeared out of sight. These were the only two photos I was able to take of the episode and I was thrilled that both turned out pretty well.

A school of mackerel scads, or Opelus being hunted by a rainbow runner off Hawaii