Tuesday, July 10, 2007

False Percula/Clownfish - Amphiprion ocellaris

The Ocellaris Clownfish, also known as the False Percula Clownfish, False Clown Anemonefish, Common Clownfish or "Nemo" from the great Disney adventure movie "Finding Nemo" is found associating with anemones throughout the Indo-Pacific. It can attain a length of 3.2" (8 cm) in the wild, but aquarium specimens rarely exceed 2" (5 cm) unless they are imported large. The color pattern is the most important feature used to identify anemonefish. Normally this clownfish has bright orange with three white bars, the middle one with a forward-projecting bulge and its bars have narrow black margin.

Clownfish has no external characteristics to differentiate male and female, all clownfish are sexually immature when hatched. Meaning that the fry do not have a pre-determined sex, they are born male with active male and dormant female reproductive organs and develop into males and females depending on the hierarchy of the school. If the female dies, then the dominant male will sex-change into a female, and a non-dominant male will change into a dominant male. This allows anemonefish inhabiting one anemone to remain self-sufficient in that if the female dies there is no need for the male to find a new mate. The responsibility for caring of the eggs becomes the "new" female's job! A pair will lay eggs along the base of the host anemone, using it to protect the eggs. The eggs normally appear orange in color. They care for their spawn by fanning the eggs with their fins, removing litter or dead eggs using their mouths with great precision, and keeping other fish away.

Anemonefish have a special symbiotic (mutaully beneficial) relationship with sea anemones. Normally, the nematocysts (stinging cells) of an anemone's tentacles discharge when fish brush against the tentacles, paralyzing the fish. But anemonefish appear to be at home among the tentacles, even hiding among them as predators approach. There are many theories concerning the mechanism that makes this possible, but the most widely held view is that these fish have a special biochemical makeup of their mucus layer that provides protection from the stinging cells.


Tuesday, June 26, 2007

Goldfish Types - Ranchu

The mighty Ranchu "King" of the goldfish of Japan! The Ranchu Goldfish is very suitable for ponds and is most striking when seen from above. The Ranchu Goldfish resembles the Lionhead Goldfish, but the posterior dorsal contour is much more curved on the Ranchu Goldfish. The Ranchu has a short, round body and short fins with no dorsal fin. One other distinguishing feature that separates the Ranchu Goldfish from the Lionhead Goldfish is the tail, which is splayed sideways with lower lobes sometimes being located nearly horizontal on the Ranchu Goldfish. The Lionhead Goldfish on the other hand, has a tail similar to the Fantail Goldfish.

The ancestors of the Ranchu date back to the late 1600s. Starting in the early 1800s during the Meiji Period (1870-1885), pictures show some signs of head growth which can be very prominent on the Ranchu of today. The history of the Ranchu Goldfish begins in China, but it was in Japan that the breed was really developed and perfected. The Ranchu goldfish is also known as Buffalo-head Goldfish.

Black Ranchu

Calico Ranchu


Goldfish - Carassius Auratus

Goldfish are the domesticated Asiatic subspecies of Carassius auratus, the gibel carp (Above), a species that naturally shows a wide range of morphological variation when raised in different environments. In its native China it inhabits rivers, streams, ponds, lakes and ditches, living in running, still and even stagnant water from 10°C to 32°C, growing to about 30 cm in length and 2.5 kg in weight within 2-3 years and living for about 10 years.

Chronology of change (mutations)
All morphological changes from the wild type are the result of genetic mutations which man has spotted and favoured by selective line breeding to perpetuate them according to his fancy, although there is a strong tendency to revert to wild type. Human husbandry of this species has unlocked its huge genetic potential, but it has taken a tremendous amount of effort to select and stabilize desirable gene combinations, as can be appreciated from the 1700-year chronology given below:

Chun dynasty (265-419) - gold colouration first recorded

Tang dynasty (618-907) - goldfish raised in captivity (in ponds) in Buddhist monasteries; common goldfish probably established

Nan Song dynasty (1127-1279) - goldfish raised in domestic ponds; white and red-and-white colouration developed

Ming dynasty (1368-1644) - goldfish raised in bowls indoors as pets, enabling selection for mutations that would not have survived (or been observed) in ponds; double tail and anal fins, dorsal-less condition and short body evolved, eggfish developed

1590 - red cap

1592 - globe eye

1596 - matt scales and calico colouration; keeping of fancy goldfish, once the preserve of the aristocracy, now widespread.

1603 - goldfish first exported to Japan

1611 - goldfish first exported to Europe (Portugal)

Ching dynasty (1644-1911) - bronze and blue colouration

1728 - goldfish first bred in Europe (Holland)

1758 - goldfish classified as Cyprinus auratus by Linnaeus (reclassified as Carassius auratus in 1949)

1870 - celestial

1874 - goldfish first exported to America

1893 - oranda/tigerhead

1900 - pompon and pearlscale; shubunkin colouration developed in Japan

1908 - bubble eye

1911 - curled operculum

early 1900s - comet and veiltail

1934 - Bristol shubunkin standard promulgated


Friday, June 22, 2007

Frontosa - Cyphotilapia Frontosa

The cichlid Cyphotilapia frontosa a.k.a frontosa is a magnificent looking species from the great lakes of East Africa. They are found in the deep waters of Lake Tanganyika at depths up to and even beyond 100 feet. Frontosas are a large cichlid with males growing from 14 to 16 inches long and females from 9 to 12 inches long.

Cyphotilapia frontosa will eat almost anything. They are primarily meat eaters so that should be considered when planning their diets in the home aquarium. Diets of the frontosa varies but some common diets include krill, adult brine shrimp, worms (blood, black, earth, etc.), feeding fish, ghost shrimp, spirulina, and more in live, frozen, flake, and pellet form.

Cyphotilapia frontosa are commonly bred in the home aquarium and many captive bred species are available from breeders. Frontosa are mouth brooders. Mouth brooding is a method of reproduction common among lake cichlids. After fertilization, the female frontosa will carry the eggs in her mouth for the incubation period. After the fry (babies) have hatched and consumed their yolk they will begin to swim outside but will retreat to the safety of their mothers mouth if threatened. After a couple of days the mother will no longer accept the fry back into her mouth. The parents will protect the fry for awhile but they will soon be on their own for survival.