Thursday, June 23, 2022

The Ancient Crab That Isn't a Crab

Fossil horseshoe crab dead in its tracks
Fossil horseshoe crab ancestor Mesolimulus an extinct arthropod

 

You might know that horseshoe crabs go back before dinosaurs. Their fossil ancestors lived 445 million years ago. (Dinosaurs appear about 200 million years later.) And they survived the extinction event that wiped dinosaurs from the planet 66 million years ago. 

There are 4 species today. In New Jersey, we know the species that is found in the Atlantic coastal waters of North America and the Gulf of Mexico. The three others are found in Asia’s coastal waters.

Did you know that are "blue bloods?" They don't have the hemoglobin that makes human blood red. Horseshoe crabs have hemocyanin which is also an oxygen-carrying protein that contains copper (our blood has iron) and that gives horseshoe crab blood a bright blue color.

That unique blood contains an enzyme that causes the blood to coagulate when exposed to deadly bacterial endotoxins, and so biomedical companies use this to test medicines, vaccines, and implants for endotoxins to insure it is safe for people. Unfortunately, many horseshoe crabs die in the process of collecting their blood. Scientists are now looking for synthetic alternatives to the enzyme.

These crabs walk on 10 legs (5 pairs) but they have another pair that they use to bring food to their mouths like arms. Without jaws, they crush worms, algae, clams, and other small prey from the ocean floor with those legs.

Those legs and its pointed tail look pretty scary to a child (and some adults!) but they are harmless. The tail (telson) is only used when a crab gets stuck upside-down so that it can flip over or as a rudder to swim upside down. When washed up on dry land, the tail isn't as effective, so if you see one it's safe to turn it over and get it back to shallow water.

That telson might not work as a sword but their tough shell is a pretty good defense for adults when they are right-side-up against other predators including sea turtles, sharks and gulls. 

Image by Chris Engel from Pixabay

Spotting a horseshoe crab in the water or on a beach is common enough at the Jersey Shore or in the bays that they even appear on t-shirts and as jewelry. Although you may spot this crab at any time of year on a Jersey beach, the most important time for them is from May to early June when they arrive on beaches to lay eggs.

The largest populations live in the Delaware Bay and they hit the beaches there during high tides that coincide with the full moon or new moon. Females dig nests in the sand and bury a cluster of about 4,000 tiny, blue-green eggs, and they can lay about 20 egg clusters each year.

That sounds like more than enough eggs but thousands of shorebirds also arrive there at that time to feast on the eggs. It is a critical food supply for migrating species such as red knots, ruddy turnstones, and sanderlings. The red knots need this final food stop before they complete their 9,300-mile migration from South America to the Arctic.

If eggs survive they will hatch in two to four weeks and the very vulnerable baby horseshoe crabs go to shallow, sheltered waters to live in for their first year as they grow and molt. 

Besides medical uses and marine and bird predators, humans use horseshoe crabs as bait to catch eels and whelk (sea snails), and that has really hurt crab populations in the past few decades.

The Atlantic horseshoe crab is currently considered “Near Threatened” by the IUCN. While not currently listed as a threatened species by the State of New Jersey, there is currently a moratorium on the harvest of horseshoe crabs within the state.

We always refer to this species as a horseshoe crab but they aren't crabs. They are arthropods and are more closely related to scorpions and spiders. They are the only living members of the Xiphosura order.

Horseshoe crab with shells 2
Sometimes you'll see them with some hitchhiking creatures attached to their shell

Monday, June 20, 2022

What Is That On My Patio?

I have occasionally gotten photos and videos over the years from people wondering what kind of animal they spotted in person or, more recently, what showed up on their security footage. Usually, they are pretty blurry and hard to identify, but I have posted some here and offered readers to play Animal Identification. 

Here is a new one from someone living in Williamstown, NJ (within Monroe Township, in Gloucester County) whose camera picked up a critter on the nation at night. It's blurry but I think some of you can identify this nocturnal footage. Unfortunately, I only have two stills - not the video.

Can you identify this NJ species?




Wednesday, June 15, 2022

Waterfall Hikes in NJ

The NJ Hiking website has some nice information if you like - as I do - hiking to a waterfall. Though waterfalls look best in the spring or after heavy rain, trails can be muddy then, so decide if you want the best view or dry boots and socks. (Winter frozen waterfalls and water is also pretty cool.) Some falls are an easy walk from a parking area and others are real ikes on trails. Their waterfall hikes collection is at njhiking.com/tag/waterfall/.

Here are just 4 examples.

Buttermilk Falls is a very short climb from a parking area up the stairs around the falls, but you can continue on the blue trail at the top, but it is steep right from the start and more than a stroll in the woods. Alternatives: Buttermilk Falls trail to an unmarked woods road to Hemlock Pond and return; roughly 5 miles. 

Ramapo Valley Falls is a short, easy hike to get to this waterfall but you can also do a longer loop hike in this popular park in Bergen County. Ramapo Valley County Reservation to Hawk Rock and Cactus Ledge viewpoints, continuing to Bear Swamp Lake, and ending with a pretty waterfall is 7.4 miles on a rocky trail surface, hills, and multiple stream crossings on rocks or logs. You can also do a short 1.4 miles yellow trail to the waterfall and back the same way.

Hemlock Falls was my childhood hike destination in Essex County and we hiked to it and biked to it from every direction. It is the tallest waterfall in South Mountain Reservation and can be reached via a short easy hike, or take in the view from historic Washington Rock on a longer hike to the falls.

Chikahoki Falls can be found in Norvin Green State Forest. This route takes in Chikahoki Falls, Otter Hole, and an awesome viewpoint at Wyanokie High Point with 360° views of the area, including NYC on a clear day. It is 7.7 miles on a rugged, rocky, path with a few decent elevation changes. There is an extensive trail system so it’s easy to create other shorter or longer loops. Ringwood, Passaic County, NJ.

Friday, June 10, 2022

Parents Only Fishing Classes at Pequest

Photo: Brett Sayles

Parents, guardians, and other family members can learn fishing basics to take back and share with your family! Spend two evenings at Pequest Trout Hatchery and Natural Resource Education Center in Oxford, NJ learning fishing basics and how to safely fish with your children. All equipment, expertise, and a trout-stocked pond are provided. 

Thursday, June 16 from 7:00 pm – 9:00 pm and
Thursday, June 23 from 7:00 pm to dusk
You must attend both sessions.

Does a child in your life want to fish, but you’ve never learned how? Mom’s, Dad’s, caregivers can spend two evenings at Pequest Trout Hatchery in Oxford, NJ learning about equipment, techniques, and tactics. At the end of this experience, you will know fishing basics and more importantly, you will be prepared to teach children how to fish safely.

Class size is limited 20 adults, 18 years and older.

To register, please go to eventbrite.com/e/parents-only-fishing-school-tickets-355180924707 

An additional pair of classes will be held Thursday, September 15 from 7:00 pm – 9:00 pm and Thursday, September 22 from 7:00 pm to dusk


More Programs and Events at the Pequest Trout Hatchery


Thursday, June 2, 2022

Free Fishing Day Is Saturday June 4


 

Haven't fished in a while, or maybe never fished? Have a friend or family member who hasn't either? Saturday is Free Fishing Day, the perfect time for New Jersey residents to try fishing the state's public waters without a license or trout stamp. All other regulations including size and daily catch limits remain in effect. 

After discovering or rediscovering the joys of fishing you and the others will need a license - so why not get Buddy Licenses together? These heavily discounted licenses go easy on your budget and let you enjoy all the fishing New Jersey offers, from small ponds to major rivers, from panfish to trophy muskellunge.

The June Free Fishing Day is held in conjunction with National Fishing and Boating Week. (The October 22 date allows the public to take advantage of the fall trout stocking.) 

New Jersey’s two Free Fishing Days are a no-risk investment for an introduction to freshwater fishing in the Garden State and the perfect time for families to enjoy two days of outdoor fun for free. Though youngsters under the age of 16 don’t need a license, these days provide a special benefit to adults who can join in the fun without having to purchase a license. That is until they get hooked on a sport that just might become a lifetime of fun for the whole family.

Find places to fish in NJ near you at nj.gov/dep/fgw/fishplc.htm