Clear Acrylic Necklace Cake Sand Dollar Specimen SD07 Clear

Description

Real Cake Sand Dollar - Arachnoides placenta specimen encased in indestructible,transparent lucite keychain. Safe,authentic and completely unbreakable product put real Specimen right at your fingertips!
Length of the specimen body is 1.7 cm (0.7 inch) .
Size of the necklace: 33x22x13.5 mm (1.3x0.9x0.5 inch)
Weight of the necklace is 15 g and 30 g with packing box.
It is a beautiful necklace and is a very good collectible item and gift for every body.
Selltotheworld
From all around the world
Clear Acrylic Necklace Cake Sand Dollar Specimen SD07 Clear
Real
Cake Sand Dollar -
Arachnoides placenta
specimen encased in indestructible,transparent lucite keychain. Safe,authentic and completely unbreakable product put real Specimen right at your fingertips!
Length of the specimen body is 1.7 cm (0.7 inch)
.
Size of the necklace: 33x22x13.5 mm (1.3x0.9x0.5 inch)
Weight of the necklace is 15 g and 30 g with packing box.
It is a beautiful necklace and is a very good collectible item and gift for every body.
This is a handmade real animal specimen craft. Each one will be a bit different (specimen size, color and posture) even in the same production batch.
The pictures in the listing is just for reference as we are selling multiple pieces with same pictures.
***
Cake Sand Dollar -
Arachnoides placenta
Order: Clypeasteroida  Family: Clypeasteridae  Genus:
Arachnoides
Arachnoides placenta
is a species of sea urchin of the family Clypeasteridae. Their armour is covered with spines. It is placed in the genus Arachnoides and lives in the sea.
Depth range 0 - 57 m
Distribution: Bay of Bengal to China and Australia.
Members of the class Echinoidea are gonochoric. Fertilization is external. Brooding is common, eggs are held either on the peristome, around the periproct or deep into the concavities on the petaloids. Life cycle: Embryos develop into planktotrophic larvae (echinoplateus) and live for several months before they sink to the bottom using their tube feet to adhere on the ground where they metamorphose into young urchins.
Sand dollars are not named after their value, but after their appearance. The skeletons (called tests) of dead sand dollars get bleached by the sun and turns white. In the past, people thought that these white skeletons of sand dollars looked like old Spanish or American dollar coins and they called them sand dollars.
Sand dollars are echinoderms, this means that they are related to sea cucumbers, sea stars and sea urchins. As a matter of fact, sand dollars are flattened sea urchins.
In comparison, sand dollars (Clypeasteroids) are irregular and flattened urchins that are adapted for thriving in fine shifting substrate, which was a habitat previously inaccessible to most other urchins. The physical changes from regular sea urchins includes the lfollowing:
1. Flattened body
The body changes from a round (spherical shape) to a flat (disc shape) skeleton like this.
2. Short spines for movement
Spines of regular sea urchins are usually elongated, but the spines in sand dollars are tiny and short, which helps them move or burrow into the sand.
Short spines and burrowing movement of a sand dollar
A distinctive trail is left behind in the sand at low tides and the sand dollar can be found just beneath the surface at the ends of these trails.
Unlike sea stars that can contour their flexible bodies to flip themselves over or sea urchins that can make use of tube feet to right themselves , sand dollars, with their rigid skeleton and tiny spines, have a much harder task of righting themselves when they are upside down. Overturned sand dollars may take up to half an hour to right themselves. They do it by digging the end of their body into the substrate and basically wait for waves or water flow to flip them back up. This is very hard for them and failure to right itself would often lead to death.
3. Jaw apparatus
The jaw apparatus of sand dollars (called the Aristotle’s lantern) is compressed and modified into a crushing mill.
evolutionary changes from regular urchins modified the lantern into a crushing mill for grinding diatoms and sand grains.
Arachnoides
is a small genus, containing of only two species. Unlike the other species (
Arachnoides tenuis
) which is restricted to only the Western Australia, the cake sand dollar is widely distributed throughout the Indo-West Pacific region.
This sand dollar is found in tropical intertidal sandy habitats [15] and prefers habitats which are permanently damp or wet. When stranded at low tide, they are usually found in pools or ripples containing wet sand. In the absence of such pools,
A. placenta
responds to reduced moisture within the sediment by burying itself deeper, especially on dry sand bars where individuals have been found at depths of 5cm.
Its distribution is patchy, and can be superabundant in certain parts of the beach while scarce in others. Adults tend to be more abundant in substrate that contains fine to medium particle size, but can also be found in coarse particle substrata, thus indicating a wide range of tolerance to various particle size. This preference for sediment grain size could be related to the effect that particle size may have on the burrowing and feeding behavior of the species.
The cake sand dollar has an orbicular body with a slightly concave base. There are no slots in the body. Colour ranges from dark purplish-grey, purple to beige. Like most sand dollars, it possesses tiny spines (cilia) that are believed to help ferry food and bury themselves into the sand.
Although colorful when alive, dead sand dollars are equally just as interesting! They may have lost their colour and spines, but every feature can be clearly seen. The aboral and oral terms are common when describing echinoderms and refer to the surface opposite the mouth and the side with the mouth respectively.
he mouth of
A. placenta
is centrally located on the oral side. The anus is near the test edge, on the aboral surface (side opposite of the mouth). It has a narrow petaloid that takes up two-thirds of the aboral surface and contains tube feet specialized for gas exchange. The oral surface possesses ambulacral grooves that extend from the test margin to the mouth.
The test diameter increases with age of the sand dollars, meaning smaller ones are younger than those bigger ones. In Singapore, the test diameter of most adult cake sand dollars ranges from 6-8cm. Sometimes juveniles, very small ones (0.6-0.8cm), can be found buried under the sand near groups of larger individuals.
The juveniles of the cake sand dollars tend to be of a pale beige (sand colour) and progressively changing to a darker purplish-brown colour in adults.
Sand dollars are not shells! Unlike snails or mollusks that have a proper shell (external to the body), sand dollars have endoskeletons. This means that the sand dollars hard skeleton lies under its skin and spines and are considered “inside” the animal’s body. This skeleton is known as a test and are made up of calcium carbonate plates.
On the inside of the test, it is hollow with a series of buttresses/pillars that passes between the top and bottom surfaces of the test. This helps to strengthen the thin test, allowing for sand dollars to survive the pounding force of the waves.
The life cycle starts with the release of sperms and eggs in the water column. Eggs are then fertilized in the water column and developed into free-swimming larvae (echinopluteus). They have long arms that are used to capture phytoplankton (small algal cells) in surface waters. For approximately two weeks, the larvae goes through several stages of development.
The larvae settles onto the substratum and metamorphosizes (process of transformation) into juveniles that have the flat skeleton. Over its lifetime, the cake sand dollar will gradually grow in size.
Like most sand dollars, the cake sand dollar crawls along the shore with their mouth facing the ground, eating microscopic particles on the sediment. Such particles of food include diatoms, blue-green algae and natural bacteria found in sediment, in the sediment.
However, the cake sand dollar is choosy in terms of the size of its food. Its dense layer of tiny spines keep out larger particles, only allowing the finer ones to move between the small spines and be transported to the mouth and Aristotle’s lantern.
In certain areas of the shore, the cake sand dollar is one of the most abundant macro-organism on sandy intertidal habitats. Other than being an important food source to other animals, they are important for the environment too. As they feed and burrow, they help to rework the sediments and may churn up nutrients, majorly influencing the physicochemical nature of the coast.
Item Specifics
Material :
Resin
Type :
Ornament
Country/Region of Manufacture :
China
Modified Item :
No
Modification Description :
NA
California Prop 65 Warning :
NA
Payment
By Paypal
Shipping
Free shipping cost.
We send the goods to USA, Canada, UK, Australia, New Zealand, EU countries and some other European and Asian countries by E-express, a kind of fast postal service by Hong Kong Post. It usually takes about 6 to 10 working days for delivery.
We send the goods to other countries by registered airmail and will take about 8 to 14 working days for delivery.
Returns
Returns: We accept returns with any reason in 30 days.
Contact Us
We will answer buyer messages within 24 hours during working days.
Selltotheworld
From all around the world
DESCRIPTION
PAYMENT
SHIPPING
RETURN POLICY
CONTACT US
Clear Acrylic Necklace Cake Sand Dollar Specimen SD07 Clear
Real
Cake Sand Dollar -
Arachnoides placenta
specimen encased in indestructible,transparent lucite keychain. Safe,authentic and completely unbreakable product put real Specimen right at your fingertips!
Length of the specimen body is 1.7 cm (0.7 inch)
.
Size of the necklace: 33x22x13.5 mm (1.3x0.9x0.5 inch)
Weight of the necklace is 15 g and 30 g with packing box.
It is a beautiful necklace and is a very good collectible item and gift for every body.
This is a handmade real animal specimen craft. Each one will be a bit different (specimen size, color and posture) even in the same production batch.
The pictures in the listing is just for reference as we are selling multiple pieces with same pictures.
***
Cake Sand Dollar -
Arachnoides placenta
Order: Clypeasteroida  Family: Clypeasteridae  Genus:
Arachnoides
Arachnoides placenta
is a species of sea urchin of the family Clypeasteridae. Their armour is covered with spines. It is placed in the genus Arachnoides and lives in the sea.
Depth range 0 - 57 m
Distribution: Bay of Bengal to China and Australia.
Members of the class Echinoidea are gonochoric. Fertilization is external. Brooding is common, eggs are held either on the peristome, around the periproct or deep into the concavities on the petaloids. Life cycle: Embryos develop into planktotrophic larvae (echinoplateus) and live for several months before they sink to the bottom using their tube feet to adhere on the ground where they metamorphose into young urchins.
Sand dollars are not named after their value, but after their appearance. The skeletons (called tests) of dead sand dollars get bleached by the sun and turns white. In the past, people thought that these white skeletons of sand dollars looked like old Spanish or American dollar coins and they called them sand dollars.
Sand dollars are echinoderms, this means that they are related to sea cucumbers, sea stars and sea urchins. As a matter of fact, sand dollars are flattened sea urchins.
In comparison, sand dollars (Clypeasteroids) are irregular and flattened urchins that are adapted for thriving in fine shifting substrate, which was a habitat previously inaccessible to most other urchins. The physical changes from regular sea urchins includes the lfollowing:
1. Flattened body
The body changes from a round (spherical shape) to a flat (disc shape) skeleton like this.
2. Short spines for movement
Spines of regular sea urchins are usually elongated, but the spines in sand dollars are tiny and short, which helps them move or burrow into the sand.
Short spines and burrowing movement of a sand dollar
A distinctive trail is left behind in the sand at low tides and the sand dollar can be found just beneath the surface at the ends of these trails.
Unlike sea stars that can contour their flexible bodies to flip themselves over or sea urchins that can make use of tube feet to right themselves , sand dollars, with their rigid skeleton and tiny spines, have a much harder task of righting themselves when they are upside down. Overturned sand dollars may take up to half an hour to right themselves. They do it by digging the end of their body into the substrate and basically wait for waves or water flow to flip them back up. This is very hard for them and failure to right itself would often lead to death.
3. Jaw apparatus
The jaw apparatus of sand dollars (called the Aristotle’s lantern) is compressed and modified into a crushing mill.
evolutionary changes from regular urchins modified the lantern into a crushing mill for grinding diatoms and sand grains.
Arachnoides
is a small genus, containing of only two species. Unlike the other species (
Arachnoides tenuis
) which is restricted to only the Western Australia, the cake sand dollar is widely distributed throughout the Indo-West Pacific region.
This sand dollar is found in tropical intertidal sandy habitats [15] and prefers habitats which are permanently damp or wet. When stranded at low tide, they are usually found in pools or ripples containing wet sand. In the absence of such pools,
A. placenta
responds to reduced moisture within the sediment by burying itself deeper, especially on dry sand bars where individuals have been found at depths of 5cm.
Its distribution is patchy, and can be superabundant in certain parts of the beach while scarce in others. Adults tend to be more abundant in substrate that contains fine to medium particle size, but can also be found in coarse particle substrata, thus indicating a wide range of tolerance to various particle size. This preference for sediment grain size could be related to the effect that particle size may have on the burrowing and feeding behavior of the species.
The cake sand dollar has an orbicular body with a slightly concave base. There are no slots in the body. Colour ranges from dark purplish-grey, purple to beige. Like most sand dollars, it possesses tiny spines (cilia) that are believed to help ferry food and bury themselves into the sand.
Although colorful when alive, dead sand dollars are equally just as interesting! They may have lost their colour and spines, but every feature can be clearly seen. The aboral and oral terms are common when describing echinoderms and refer to the surface opposite the mouth and the side with the mouth respectively.
he mouth of
A. placenta
is centrally located on the oral side. The anus is near the test edge, on the aboral surface (side opposite of the mouth). It has a narrow petaloid that takes up two-thirds of the aboral surface and contains tube feet specialized for gas exchange. The oral surface possesses ambulacral grooves that extend from the test margin to the mouth.
The test diameter increases with age of the sand dollars, meaning smaller ones are younger than those bigger ones. In Singapore, the test diameter of most adult cake sand dollars ranges from 6-8cm. Sometimes juveniles, very small ones (0.6-0.8cm), can be found buried under the sand near groups of larger individuals.
The juveniles of the cake sand dollars tend to be of a pale beige (sand colour) and progressively changing to a darker purplish-brown colour in adults.
Sand dollars are not shells! Unlike snails or mollusks that have a proper shell (external to the body), sand dollars have endoskeletons. This means that the sand dollars hard skeleton lies under its skin and spines and are considered “inside” the animal’s body. This skeleton is known as a test and are made up of calcium carbonate plates.
On the inside of the test, it is hollow with a series of buttresses/pillars that passes between the top and bottom surfaces of the test. This helps to strengthen the thin test, allowing for sand dollars to survive the pounding force of the waves.
The life cycle starts with the release of sperms and eggs in the water column. Eggs are then fertilized in the water column and developed into free-swimming larvae (echinopluteus). They have long arms that are used to capture phytoplankton (small algal cells) in surface waters. For approximately two weeks, the larvae goes through several stages of development.
The larvae settles onto the substratum and metamorphosizes (process of transformation) into juveniles that have the flat skeleton. Over its lifetime, the cake sand dollar will gradually grow in size.
Like most sand dollars, the cake sand dollar crawls along the shore with their mouth facing the ground, eating microscopic particles on the sediment. Such particles of food include diatoms, blue-green algae and natural bacteria found in sediment, in the sediment.
However, the cake sand dollar is choosy in terms of the size of its food. Its dense layer of tiny spines keep out larger particles, only allowing the finer ones to move between the small spines and be transported to the mouth and Aristotle’s lantern.
In certain areas of the shore, the cake sand dollar is one of the most abundant macro-organism on sandy intertidal habitats. Other than being an important food source to other animals, they are important for the environment too. As they feed and burrow, they help to rework the sediments and may churn up nutrients, majorly influencing the physicochemical nature of the coast.
Item Specifics
Material :
Resin
Type :
Ornament
Country/Region of Manufacture :
China
Modified Item :
No
Modification Description :
NA
California Prop 65 Warning :
NA
Payment
By Paypal
Shipping
Free shipping cost.
We send the goods to USA, Canada, UK, Australia, New Zealand, EU countries and some other European and Asian countries by E-express, a kind of fast postal service by Hong Kong Post. It usually takes about 6 to 10 working days for delivery.
We send the goods to other countries by registered airmail and will take about 8 to 14 working days for delivery.
Returns
Returns: We accept returns with any reason in 30 days.
Contact Us
We will answer buyer messages within 24 hours during working days.
All right reserved.
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