Crabology 101: All about crabs and bait

[surferman]

How about some info about crabs? What kind do you use for bait for stripers? How do you fish them and whats some tips for looking for them?

[DarkSkies]

We've been talking about seeing crabs lately. Wanted to make sure the people running into them had a better understanding of what they're looking at, and the different distinctions.

I know guys who you would consider "crabologists". I'm not one, not enough knowledge yet. Some of these guys take collecting crabs down to a science. If you want to catch bass consistently with crabs in the summer, it takes some serious work, and the willingness to set up a crab tank, if ya wanna take it that far, for the bigger bass.

When the baitfish aren't around, resident bass gotta eat something. They're snacking on the crabs in and around the rocks. A little crunchy, but bass ain't that particular when they're searching for natural forage sometimes.

Anyone has anything to add in here, what you're using and how ya do it, feel free.

[DarkSkies]

http://en.wikipedia.org/wiki/Lady_crab


The lady crab or calico crab, scientific name Ovalipes ocellatus, is a species of marine swimming crab.
Contents

[hide]

• <LI class="toclevel-1 tocsection-1">1 Distribution <LI class="toclevel-1 tocsection-2">2 Habitat <LI class="toclevel-1 tocsection-3">3 Description <LI class="toclevel-1 tocsection-4">4 Life habits
  
  • 4.1 Reproduction and growth
• 5 See also

[edit] Distribution

The lady crab is found in the Western Atlantic Ocean from Cape Cod to Texas.
[edit] Habitat

This species of crab is most often found in sandy substrates in quite shallow water, i.e. the surf zone. Normally, this is a very difficult habitat, because of strong wave action and constantly shifting sands. This animal escapes these dangers by burrowing just beneath the sand surface. As waves toss the sand around, the crab quickly shifts position and digs back under the surface.
[edit] Description

The claws of the lady crab are not particularly large, but they are sharp. The hind pair of legs are flat and paddle-shaped for swimming when necessary. The crab grows to be 4 in (10 cm) wide.
The carapace of this crab has projections known as "frontal teeth" between the eye sockets. The teeth behind the eyes are known as marginal teeth. The lady crab has three frontal teeth, and five marginal teeth on each side.
[edit] Life habits

The lady crab feeds on live or decaying marine organisms such as fish, crabs, or clams; this means it is both a predator and a scavenger. When fish or worms pass by, it comes out of the sand and grabs the animal with its claws.
Like other swimming crabs, the lady crab does not have a very thick or rigid carapace. This means it has less protection than some other crabs, which have harder shells or exoskeletons. Because it is not very well protected, it makes up for this by its speed and camouflage.
The lady crab has compound eyes at the tip of stalks, which allows it to be aware of predators.
[edit] Reproduction and growth

As is true of most crabs, males and females are distinguished by looking at the abdominal flap beneath their bodies. The female has a wide flap in order to carry the eggs, while the males have a thin flap. Once the eggs hatch, they are planktonic. The juvenile crabs do not resemble their parents until they have molted several times over the next few weeks. As they grow, they pass through two main stages called the zoea and megalopa before becoming an adult.
The lady crab molts as it grows, like most arthropods. These crabs appear to stop molting when they reach 4 in wide. Adults that have stopped molting are often covered in growths of barnacles or seaweed.

[DarkSkies]

These are good crabs to use as well, not as effective as the calicos, but still effective if you can get them when shedding. They are one of the most abundant species you will find, and it's said they will soon take over. So don't feel bad about using them, ya really can't deplete this resource.

Quick way to differentiate is they have bigger claws, but more rounded and less pointed, than the regular ones.

Japanese Shore Crab (Hemigrapsus sanguineus)

Photo credit: Copyright Koyou Crab Information, KoreaCredit: This web page was first developed by Jessica D. Sharon.
DESCRIPTION The Japanese shore crab’s identifiable features are a small hard bubble at the crux of its claws; three spines along each side of its shell (carapace), as opposed the similar-looking green crab which has five; and a light-and-dark banding pattern on its legs. The crabs grow to about the size of a silver dollar.
The crabs inhabit the rocky intertidal zone — between the high tide line and about one or two feet below low tide. They are omnivorous, eating macroalgae, salt marsh grass, and small invertebrates such as amphipods, gastropods, bivalves, barnacles and polychaetes. To the south, the crabs’ diet consists of mussels, clams, periwinkles and the European Green Crab (the latter two are also non-native species). The crab is able to reproduce several times a year. Whether the crab will have similar dietary preferences or be able to reproduce as frequently in Maine’s colder climate remains to be seen.

Size and Features: 2-3 inches, total width; carapace with three spines on each side
Habitat: Intertidal, rocky areas having cobble bottoms
Physical Appearance: Light and dark bands along its legs; red spots on its claws; and a body color ranging from pink to green to brown and even purple, depending on where it is found
Seasonal Appearance: Early spring to late fall
Behavior: Aggregate under rocks; not overly aggressive (Neils Hobbs, Department of Biological Sciences at the University of Rhode Island.)

Photo credit: Professor Larry Harris, University of New Hampshire (Source: 1. Japanese Shore Crab, Department of Marine Resource, http://www.state.me.us/dmr/rm/asian_shore_crab.htm 2. Creature Feature: Japanese Shore Crab; The Bay's Uninvited Guest, by Mac Richardson, Save the Bay, http://www.savebay.org/aboutus/winte...re_feature.htm)

[DarkSkies]

Some interesting stuff




IMPACTS

The Japanese Shore Crab is slowly overtaking the habitat of native crabs, such as green crabs and mud crabs. This tiny invader is becoming more dominant while the numbers of resident crabs slowly decline. This is due, in part, because it is an opportunistic omnivore; essentially eating anything that it's offered.An omnivore with an appetite for young clams, scallops, oysters, algae, fish larvae, and many other species, these crabs may well pose a threat to New England ecosystems and aquaculture operations. This new competition in the food chain is leaving many other species struggling. Although the total impact of this species is not yet know, many are questioning whether or not there could be a link between the recent collapse of the lobster population in Long Island Sound, Maine. Others are concerned that perhaps there's a connection between the rise of the Japanese crab and the decline of the blue crab populations in the Chesapeake Bay.

(Source: 1. Tiny Invader Becomes a Bully in Local Waters, June 10, 2001, by John McQuiston, The New York Times http://www.seagrant.sunysb.edu/Media...-ANS061001.htm ; 2. A Quick Guide to Marine Bioinvaders, MIT Sea Grant College Program, http://web.mit.edu/seagrant/bioinvade/japcrab.html)

Top




ORIGIN
Japanese Shore Crab was first identified on American shores in New Jersey in 1988. It's since made its way as far north as Portland, Maine, and as far south as North Carolina. The crab is indigenous to waters from southern Russia to Hong Kong The Japanese shore crab is invading Long Island Sound and crowding out native species, according to marine biologists. (Source: 1. Japanese Shore Crab, Department of Marine Resource, http://www.state.me.us/dmr/rm/asian_shore_crab.htm


DISTRIBUTION Link to Nonindigenous Crustaceans in the United States Distribution Map (Florida Caribbean Science Center) Link

http://www.fcsc.usgs.gov/posters/Nonindigenous_Crustaceans/nonindigenous_crustaceans.html

Crustaceans
(Focus on the Great Lakes)
1999 LinkPresented by Amy J. Benson and Pam L. Fuller
U.S.Geological Survey, Biological Resources Division Top



Control Japanese Shore Crab


While there are not yet chemical and biological methods to control this species, there are many suggestions that can be followed in order to work towards eradication. Suggestions include establishing a database of current status of invasive species, monitoring changes in "residency" of existing invasive species populations, increasing public awareness, monitoring ballast water discharge from freighters, and sending posters and fact sheets to parks, beaches, or recreation areas.

Each person plays an important role in preventing the introduction of non-native species, Here are some suggestions on how you can help:.

• Don't transport plants and animals when you travel or move without checking with local authorities.
• Never release pets, aquarium plants or animals or non-native plants into the wild.
• Plant only native plants on your property.
• Be familiar with the pathways through which non-native species can enter our lands and waters and do your part to stop their accidental release or movement.
• Report any sitings of known or suspected invasive species to your state natural resource agency. A record of these sitings is necessary to determine the distribution of these species and monitor their effect.

(Source: 1. Three new Exotic Species of the Chesapeake and Coastal Regions, Maryland Recreational Fisheries,

[DarkSkies]

This comes to us courtesy of Scott's B&T, THE tackle place to visit when you fish the Mystic Island NJ area.

www.scottsbt.com/misc/crabbing/baitcrabs.htm

Info on Whiteleggers

This is a tough one...when you look up whiteleggers online you get all kinds of conversations about what crabs they are..but nothing concrete. I think that many folks have tagged multiple crabs with this nickname...listing them below. They are apparently very tasty to the Tautog...if you can find any local sources for them.



Atlantic Rock Crab
Fly lure w/crab info
Rock Crab info



Calico (Lady) Crab
http://en.wikipedia.org/

Jonah Crab
http://en.wikipedia.org/

[buckethead]

Some interesting stuff




IMPACTS

The Japanese Shore Crab is slowly overtaking the habitat of native crabs, such as green crabs and mud crabs. This tiny invader is becoming more dominant while the numbers of resident crabs slowly decline. This is due, in part, because it is an opportunistic omnivore; essentially eating anything that it's offered.An omnivore with an appetite for young clams, scallops, oysters, algae, fish larvae, and many other species, these crabs may well pose a threat to New England ecosystems and aquaculture operations. This new competition in the food chain is leaving many other species struggling. Although the total impact of this species is not yet know, many are questioning whether or not there could be a link between the recent collapse of the lobster population in Long Island Sound, Maine. Others are concerned that perhaps there's a connection between the rise of the Japanese crab and the decline of the blue crab populations in the Chesapeake Bay. ,

Dark, outstanding job on the research and teaching you have done in this thread.
I have been raking crabs for the last 2 months. Fish to 24 pounds. Last night got one that was 13.

You can also use the Asian shore crabs (you refer to them as the Japanese shore crabs) as well. What it seems to me is the calicos and whiteleggers are better. The Asians work but as they are smaller you tend to get skates and other small nuisance fish like sea robins. If I am going to the trouble to rake crabs I certainly don't want to feed them to skates.
But, just for you fellas to know that the Asians will work in a pinch. They do have to be shedding though or it will not work.

Here is some more info I found on the Asians.


http://fl.biology.usgs.gov/Nonindige...hore_crab.html

Printable PDF Format

NONINDIGENOUS SPECIES INFORMATION BULLETIN
Asian shore crab, Japanese shore crab, Pacific crab,
Hemigrapsus sanguineus (De Haan)
(Arthropoda: Grapsidae)

IDENTIFICATION: The Asian shore crab has a square-shaped shell with 3 spines on each side of the carapace. The carapace color ranges from green to purple to orange-brown to red. It has light and dark bands along its legs and red spots on its claws. Male crabs have a distinctive fleshy, bulb-like structure at the base of the moveable finger on the claws. This species is small with adults ranging from 35 mm (1.5 in) to 42 mm (1.65 in) in carapace width. NATIVE RANGE: Hemigrapsus sanguineus is indigenous to the western Pacific Ocean from Russia, along the Korean and Chinese coasts to Hong Kong, and the Japanese archipelago.

Asian Shore Crab (Hemigrapsus sanguineus) (Specimen courtesy of Susan Park, University of Delaware)

LIFE HISTORY: This species is an opportunistic omnivore, feeding on macroalgae, salt marsh grass, larval and juvenile fish, and small invertebrates such as amphipods, gastropods, bivalves, barnacles, and polychaetes. The Asian shore crab is highly reproductive with a breeding season from May to September, twice the length of native crabs. The females are capable of producing 50,000 eggs per clutch with 3-4 clutches per breeding season. The larvae are suspended in the water for approximately one month before developing into juvenile crabs. Because of this, the larvae have the ability to be transported over great distances, a possible means of new introductions.


HABITAT: This versatile crab inhabits any shallow hard-bottom intertidal or sometimes subtidal habitat. They can live on artificial structures and on mussel beds and oyster reefs. They also tend to aggregate at high densities under rocks where they overlap habitats with native crab species. Hemigrapsus can tolerate wide ranges of salinity and temperature as well as damp conditions in the upper intertidal regions.

NONINDIGENOUS OCCURRENCES: Hemigrapsus was first recorded in the United States at Townsend Inlet, Cape May County, New Jersey in 1988. This species is now well established and exceptionally abundant along the Atlantic intertidal coastline of the United States from Maine to North Carolina. It is actively breeding and expanding its population within its nonnative range. Because the species is tolerant of a wide range of environmental conditions, it is likely that the invasion will continue along the US coastline.

MEANS OF INTRODUCTION: It is not known how this species was introduced to the United States Atlantic coast, but many speculate that adults or larvae were brought by incoming ships of global trade via ballast water discharge.

Hemigrapsus sanguineus locations in the United States

IMPACTS: Because this species has a very broad diet, it has the potential to affect populations of native species such as crabs, fish, and shellfish by disrupting the food web. It also occupies habitats very similar to our native mud crabs, possibly overwhelming and dominating their habitat. This potential impact on native species populations may be a result of direct predation or competition for a food source. Hemigrapsus may compete with larger species, like the blue crab, rock crab, lobster, and the nonnative green crab. Recent trends show numbers of shore crabs are steadily increasing while native crab populations are declining. These opportunistic omnivores may also pose threats to coastline ecosystems and aquaculture operations. There are still many questions to be answered by scientists about impacts this species may pose to biodiversity in those ecosystems affected.

CONTROL AND MANAGEMENT: Preliminary evidence shows that rockfish and seagulls may prey upon Hemigrapsus. Parasites, which help control populations of Hemigrapsus in its native range, are not present along the US Atlantic coast. The shore crab may continue to expand its range along the US Atlantic coastline until it reaches its salinity and temperature tolerance levels. Scientists are monitoring changes in native species, tracking the shore crab's spread along the coastline, and conducting experiments to increase their knowledge of basic biology and ecology of this species. Ballast water management is also being researched to reduce or eradicate new introductions from occurring.

Printable PDF FormatPhoto GalleryIf you have collected or observed this species, or know of someone who has, please call the Nonindigenous Aquatic Species Toll-Free Hotline, 1-877-STOP-ANS and report the information. Or, report it to http://nas.er.usgs.gov/SightingReport.asp or,Amy Benson amy_benson@usgs.gov

[chas527]

took a walk along the beach in portmonmouth.i counted 105 dead horseshoe crabs, in just a mile.does any body know why they are dying.

[basshunter]

^^^Possible too much algae or too little oxygen. MHO.
nice report steve. finchaser happy to hear about bigger blues there have been a lot of aggressive snappers eating my gulp for the last few weeks its time for a change.

[paco33]

Chas something I found on horseshoe crabs. Dont know if it applies to where you are.

Pollution also is a possible threat to horseshoe crabs. People are using more pesticides on their lawns and farmland, and New Jersey and Delaware are spraying more for mosquito control. As a result, you get more chemicals washing into the water from the urban and agricultural runoff. Junk in the water causes problems, too. Sewage, factory waste, rainwater carrying pollutants from parking lots, yards and streams can kill clams and other animals that crabs use for food. Water pollution may weaken or kill horseshoe eggs and larvae.
http://library.thinkquest.org/J0110020/threat.html

[ledhead36]

Chas I know that area you were walking in. Paco may be right with some of the possibilities he posted. Also around this time of year the water back there gets stagnant. I don't know if you remember this but in the last 10 years we have had fishkills at least 2 times that I recall. Massive peanut bunker die offs. Maybe it has something to do with the lower summer oxygen levels which also kills the fish. Haven't seen any dead peanut bunker or mullet back there this year so I am not certain. That water does get funny though when there aren't a lot of storms.
Also sometimes there are immigrants who fish along that shoreline. They hate the horseshoe crabs when they hook up with them and leave them on the beach.
Same thing with the sea robins. I believe madcaster posted a pic of a dead circle of sea robins in the dead things thread.

[J Barbosa]

For the rest of you shore bound crabbers its time to get your last few crabs in for the season.

With the cooling overnight temps those crabs are one of the first species to begin moving out into deeper water.

My dad and brother were only able to catch six legal sized crabs in three hours...two per hour! Normal catch would have been a few dozen. They went early in the morning after a cool night, the afternoon would have been better.

I've already hung my crabbing nets away until May 2014.

It was a good year for crabbers in NJ!

Look out for a possible crabbing 201 tutorial over the winter.