Archive for October, 2018


TAXONOMY
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii (ray-finned fishes)
Order: Lepisosteiformes (Gars) 
Family; Lepisosteidae (Gars)

Genus/species: Atractosteus spatula

GENERAL CHARACTERISTICS: Alligator-like. Large size and broad, short, wide, blunt snout and a heterocercal tail. Color is dark olivaceous brown above and white to yellowish beneath with dark brown blotches on all fins. Body is covered with armor-like ganoid scales consisting of diamond-shaped, interlocking, and extremely hard bony plates covered with layers of dentine and enamel. Head protected by bony plates. Alligator gars have two rows of teeth, a longer one on the palate, and an outer row in the jaw, enabling them to pierce and hold prey. A. spatula is the largest exclusively freshwater fish found in North America.

Alligator gar are the largest gar species. with a length up to than 3 m (9.8 ft), weight to 137 kg (300 pounds).

Alligator Gar 8362889461_f8706ce1f4_b

DISTRIBUTION/HABITAT: Alligator Gar are found in lakes, rivers, and bayous from the Mississippi to the Gulf coast in fresh and brackish water.

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DIET IN THE WILD: They are opportunistic carnivores and sit-and-wait predators. They appear to be sluggish, but can ambush prey with short bursts of speed feeding on almost anything, including fish, ducks, turtles, small mammals, and carrion

REPRODUCTION: Females reach sexual maturity at 11 years. Eggs laid on aquatic vegetation, to which they adhere. Young cling to the stems with an adhesive disc on their head until yolk sac is absorbed, and then swim actively. Juveniles feed on plankton, invertebrates, amphibians, and fish before transitioning to fish almost exclusively.
The eggs of alligator gar are bright red and poisonous to humans if ingested.

MORTALITY: Females generally larger and longer lived than males. Some may live to 50 years or more in the wild, 80 years in captivity. The Academies oldest gars are in their 60s.

CONSERVATION STATUS: Not on IUCN Red List. Pollution and degradation of habitat threaten this species.

alligator garIMG_2863

 

REMARKS: Gars also have a highly vascularized swim bladder directly connected to its throat that enables them to breathe in air, an adaptation to life in water with low oxygen levels. Native Americans used armor-like ganoid scales as arrowheads and jewelry. Early American farmers used the scales on the blades of their plows.

The fossil record traces their existence to the Early Cretaceous over a hundred million years ago.there is no documentation of attacks on man by alligator gars.

There is no documentation of an attack on man by alligator gars.

References

California Academy of Sciences Steinhart Aquarium Swamp 2018

Ron’s flickr http://www.flickr.com/photos/cas_docents/sets/72157608608528651/with/8362889461/

Ron’s WordPress Shortlink http://wp.me/p1DZ4b-103

fishbase. www.fishbase.se/summary/Atractosteus-spatula.html

ADW. animaldiversity.org/accounts/Atractosteus_spatula/

 

 

6-7-13, 1-19-17, 10-9-18

VIDEO LINK https://www.flickr.com/photos/cas_docents/5443993471/in/album-72157659528522603/

YOUTUBE LINK  http://youtu.be/ei1Pe7r2kdI

TAXONOMY
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Octopodidae
Genus/:Species: Enteroctopus dofleini

GENERAL CHARACTERISTICS: Giant Pacific octopuses are the largest species of octopus. Their large bulbous “head” (mantle) has 8 tentacles each bearing up to 280 suckers which have thousands of chemical receptors used to help detect prey. Very large specimens can have a tentacle span of more than 9 m (29 feet) from tip to tip, and weigh more than 45 kg (100 pounds).

DISTRIBUTION/HABITAT: Range throughout temperate Pacific waters, from southern California north to Alaska, west to the Aleutian Islands and Japan.
Giant Pacific octopuses are generally found in tidal pools and up to depths of 110 m (360 ft), although they can also reside in deeper waters of up to 1,500 m (4900 ft). They often live in dens or lairs, under boulders, and in rock crevices. Ideal habitat for this species includes a soft substrate of mud, sand or gravel that includes large boulders for creating dens.

DIET IN THE WILD: E. dofleini feed mostly on crustaceans (shrimps, crabs, scallops,) and mollusks (abalones, clams); fish and other octopuses are also Shells of prey that are difficult to pull or bite open can be “drilled” in order to gain access to the soft tissue: salivary secretions soften the shell, and a tiny hole is created with the radula (a toothed, hardened “tongue”). The octopus then secretes a toxin that paralyzes the prey and begins to dissolve it. The shell is pulled apart and the soft tissues are consumed.

REPRODUCTION: Lays up to 75,000 eggs in small caves where the female defends them until they hatch, which takes up to six months. The hatchlings then drift in ocean currents for several months, settle to the seafloor. Reproduction starts when they are one year old.

MORTALITY/LONGEVITY: Predators include marine mammals (harbor seals, sea otters, and sperm whales). Also, occasionally are eaten by others of their own kind and are caught commercially. Life span is 4.5 to 5 years in the wild and captivity.

REMARKS:

They can move more than 700 pounds using all of their arms.

It is considered one of the most intelligent of all invertebrates.

References

California Academy of Sciences, Steinhart Aquarium 2018

Ron’s WordPress Link  http://wp.me/p1DZ4b-h5

Arkive www.arkive.org/north-pacific-giant-octopus/enteroctopus-d…

ADW animaldiversity.org/accounts/Enteroctopus_dofleini/

Cephalopod Page www.thecephalopodpage.org

YOUTUBE LINK  http://youtu.be/ei1Pe7r2kdI

Ron’s flickr link  http://www.flickr.com/photos/cas_docents/sets/72157608597736188/with/5443993471/

TAXONOMY
Kingdom: Animalia
Phylum: Cnidaria
Class: Scyphozoa
Order: Semaeostomeae
Family: Pelagiidae

Genus/species: Chrysaora fuscescens

GENERAL CHARACTERISTICS: The sea nettle is a giant, semitransparent jellyfish, with an amber-colored, swimming bell commonly as large as 30 cm (12 inches) in diameter, with some measuring more than a meter. In addition to four oral arms attached to the underside of the mouth, the sea nettle has 24 long tentacles around the perimeter of the bell that extend up to 4 m (13 ft).

DISTRIBUTION/HABITAT: Marine, found along the westcoast of North America from Mexico to British Columbia.

DIET IN THE WILD: Carnivorous; feeds on zooplankton, small crustaceans, comb jellies, fish eggs and larvae. Sea nettles sting their prey with their tentacles, which have millions of microscopic stinging cells that inject toxins to stun or kill tiny animals. The main oral arms then transport food to the heart-shaped gastric pouches in the bell, where digestion occurs.


PREDATORS: In the medusa stage, sea nettles live from 2–6 mos, usually perishing in rough waters or being eaten by predators— ocean sunfish and leatherback turtles are two of the most prevalent jellyfish predators.

REMARKS: Question: What has no heart, bones, eyes or brain, is made up of 95% water, and yet
is still a remarkably efficient ocean predator? (The jellyfish) Some jellies commute 3,600 feet (1,097 m) up and down in the water column daily!

Sea nettle stings can result in extreme localized pain. Fortunately this jelly is not aggressive.

The bell of this and other jellies is called a “medusa” because, with its long, fringing tentacles, it resembles the snake-haired Gorgon Medusa of Greek mythology.

Venomous, Plankton/Sea Drifters

References

California Academy of Sciences Steinhart Aquarium 2018

Monterey Bay Aquarium www.montereybayaquarium.org/animal-guide/invertebrates/se…

Rons flickr www.flickr.com/photos/cas_docents/sets/72157610031545571/…

Rons WordPress Shortlist wp.me/p1DZ4b-PM

10-2-18

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