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198707 [2016/09/16 12:04] – tyreless198707 [2016/09/16 12:16] – tyreless
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-WHAT'S BITING YOU?!! - CRAYFISH. +=====What's Biting You?!! - Crayfish.===== 
-' BY Geoff McIntosh. + 
-Yes, bushwalkers have been bitten by crayfish. Peter Christian and Rudi Dezelin +By Geoff McIntosh. 
-suffered razor-like cuts to their digits on a McCarrs Creek daywalk in Ku-ring-gai Chase National Park about three years ago because they were not careful when picking up crayfish.+ 
 +Yes, bushwalkers have been bitten by crayfish. Peter Christian and Rudi Dezelin suffered razor-like cuts to their digits on a McCarrs Creek daywalk in Ku-ring-gai Chase National Park about three years ago because they were not careful when picking up crayfish. 
 There is much interchange and variation in nomenclature throughout Australia involving crayfish, yabbies and lobsters. "Yabby" is an aboriginal word. There is much interchange and variation in nomenclature throughout Australia involving crayfish, yabbies and lobsters. "Yabby" is an aboriginal word.
 +
 There are approximately 400 species of freshwater crayfish on earth, with approximately 100 of these species in Australia. There are approximately 400 species of freshwater crayfish on earth, with approximately 100 of these species in Australia.
-Australia has the largest freshwater crayfish and also the smallest. The largest is + 
-the Astocopsis gouldi from small streams in North-west Tasmania and measures 76 cm (30 inches) from claws to tail. The smallest is the Tenuibranchiurus which measures 2 cm (3/4 inch) long and is found in Queensland. +Australia has the largest freshwater crayfish and also the smallest. The largest is the Astocopsis gouldi from small streams in North-west Tasmania and measures 76 cm (30 inches) from claws to tail. The smallest is the Tenuibranchiurus which measures 2 cm (3/4 inch) long and is found in Queensland. 
-Biology of the Crayfish. + 
 +===Biology of the Crayfish.=== 
 The crayfish is a decapod (ten-legged) crustacean which evolved during the Mesozoic era between 130 and 225 million years ago, the period during which the dinosaur appeared and disappeared. The crayfish is a decapod (ten-legged) crustacean which evolved during the Mesozoic era between 130 and 225 million years ago, the period during which the dinosaur appeared and disappeared.
 +
 The crayfish has two gill compartments whose cover can be closed to trap moisture allowing it to live out of water for short periods (much longer for semi-aquatic and terrestrial crayfish). It has a simple brain; compound eyes; touch receptors in its antennae, walking legs and body; chemical receptors for tasting in its antennules and on the walls of the gill chambers; and odour detectors in its antennae. The crayfish has two gill compartments whose cover can be closed to trap moisture allowing it to live out of water for short periods (much longer for semi-aquatic and terrestrial crayfish). It has a simple brain; compound eyes; touch receptors in its antennae, walking legs and body; chemical receptors for tasting in its antennules and on the walls of the gill chambers; and odour detectors in its antennae.
-Moulting. + 
 +===Moulting.=== 
 The crayfish has an external skeleton and to grow must moult as follows: The crayfish has an external skeleton and to grow must moult as follows:
-1. Calcium is withdrawn from the skin and stored. + 
-2. A new soft folded skin forms beneath the old skin. +  - Calcium is withdrawn from the skin and stored. 
-3. The old skin splits and the crayfish steps out. +  - A new soft folded skin forms beneath the old skin. 
-4. The crayfish grows quickly within its soft skin. +  - The old skin splits and the crayfish steps out. 
-5. The crayfish draws calcium into the new skin from its calcium storage areas and the surrounding water, and from eating its old skin. +  - The crayfish grows quickly within its soft skin. 
-6. The new skin hardens. +  - The crayfish draws calcium into the new skin from its calcium storage areas and the surrounding water, and from eating its old skin. 
-During successive moults, the crayfish can gradually replace lost legs, claws, antennae and antennules,but not its eyes which are replaced by another set of antennules. +  - The new skin hardens. 
-Locomotion.  +   
-The paddle-like swimmerets are used to aerate the crayfish and propel it forward. The +During successive moults, the crayfish can gradually replace lost legs, claws, antennae and antennules, but not its eyes which are replaced by another set of antennules. 
-high speed reversing from danger with claws at the ready is achieved by quickly closing the tail to produce a jet of water. + 
-Reproduction of Crayfish. +===Locomotion.=== 
 + 
 +The paddle-like swimmerets are used to aerate the crayfish and propel it forward. The high speed reversing from danger with claws at the ready is achieved by quickly closing the tail to produce a jet of water. 
 + 
 +===Reproduction of Crayfish.=== 
 The male throws the female on her back and mounts her, spaying sperm from his two penes on to her two genital openings. The female passes hundreds of eggs through the sperm, fertilising them, then pushes the eggs down to the underside of her tail where they stick firmly and are aerated by the waving of the swimmerets. The male throws the female on her back and mounts her, spaying sperm from his two penes on to her two genital openings. The female passes hundreds of eggs through the sperm, fertilising them, then pushes the eggs down to the underside of her tail where they stick firmly and are aerated by the waving of the swimmerets.
-The hatched crayfish grow from the eggs, then moult and hang upside down on her swimmerets. (In the northern hemisphere, they hang right side up.) On moulting again they become + 
-facsimiles of the adults and leave Mum permanently.+The hatched crayfish grow from the eggs, then moult and hang upside down on her swimmerets. (In the northern hemisphere, they hang right side up.) On moulting again they become facsimiles of the adults and leave Mum permanently. 
 Mating is in spring and summer. Mating is in spring and summer.
- Foolgf, Crayfish are mostly vegetarian, but will eat almost anything if need be, including + 
-each other. +===Food.=== 
-Page 8 THE SYDNEY BUSHWALKER July, 1987 + 
-Walking Legs +Crayfish are mostly vegetarian, but will eat almost anything if need be, including each other. 
-(AI3DY (cueRAX 1>E5rgUCTOR) + 
-TAE MuSRAy CRAY +===Types  of Australian Crayfish.=== 
-The Sy104EY CAAYFISPI HAVE + 
-A SIMILAR APPEARAAJCS , +Australian freshwater crayfish are classified in three broad groups: 
-Cmapece + 
-Gah under this section) +  - Aquatic Freshwater Crayfish (of which the Sydney Crayfish is one) occur only in permanent rivers, creeks and sometimes lakes. 
-Cervical Groove +  - Semi-Aquatic Freshwater Crayfish live in burrows connected to water (dams, rivers etc. which are not necessarily permanent) by access shafts and are capable of surviving out of water for long periods. One species, the Chera destructor, as mentioned previously is known by an aboriginal word, "yabby", and inhabits about one third bf Australia. (Refer: map.) 
-Antennuie +  - Terrestrial Freshwater Crayfish live anywhere on land provided there is water with 2 metres (6 feet) of ground level. 
-Walking Legs +   
-Ceptialothorax (Head & Thorax) +===The Australian Aquatic Freshwater Crayfish -=== 
-1 + 
-Abdomen +Has several genuses, the main one being the Euastacus (Spiny Freshwater Crayfish). There are 27 species of this genus around Australia, the main ones being:- 
-Chelipid + 
-Antennae +1. __The Sydney Crayfish__. 
-Antennults + 
-Cervical Groove +(a) Ebastacus australasiensis which occurs in creeks around Sydney. The young are a muddy brown colour changing through moults to a bright orange in the adults. They grow to about 20 cm (8 inches) from head to tail. 
-140R714 QI)ED0SIAAA SPIPP( egArA54i + 
-CittASTAcu FL-8 CK 11) +(b) Evastacus spinifera which occurs in creeks north of Sydney Harbour. They are usually dark greenish with red markings. 
-YA 8T (CHERAK 1)6;TKLICTeit) + 
-LA AA 14GrON SPINY Cg4YFIC14 +2. __The Murray Crayfish__.  
-(EVA STA CoS SuL4A-ra5) + 
-MARRokl +Evastacus armatus is the second largest freshwater crayfish on earth measuring 45 cm (18 inches) from head to tail and is found in the Murray River and many of its tributaries. 
-RAX TUN MAWS)  + 
-MuRgAY R, CRAy PAPAW( +3. __The Lamington Spiny Crayfish__. (Euastacus sulcatus) 
-'MUM! M + 
-la  011PINP (EvASTAcvS S Prat 5) +Is well known to walkers in the beautiful rainforest of the Lamington National Park in south-east Queensland, its only domicile. It is the most spectacular species with bands of bright blue and white with scarlet at its joints. It is sometimes seen walking along the well-graded tracks of the park, hundreds of metres from its creeks in wet weather. When approached it will rear up, waving its large claws and hissing. A threatening sight, even though it only appears to grow to about 22 cm (9 inches) long from head to tail. 
-'A5rAC/OPP/5 Gout 1.1 + 
-(61,017 7-A5MAAJIA,A1 CRAyFISAI-5-----111b-t) sybNIET CRAYE1514 +4. __The Gippsland Crayfish__ - of Victoria. 
-tuAflACIIS lieSTRAMSai.isiS i) + 
-SPIN WERA +5. __The North Queensland Spiny Crayfish__. (Euastacus fleckeri) 
-MAZOR FRE5RWATE1 CRAYFI5A/ GROUP$ + 
-July, 1987 THE SYDNEY BUSHWALKER Page 9 +Is found only in the Daintree River and Mossman River areas. 
-Ii2es  of Australian Crayfish.  + 
-Australian. freshwater crayfish are classified in three broad groups: +===Sources of Informtion.=== 
-1. Aquatic Freshwater Crayfish (of which the Sydney Crayfish is one) occur only in permanent rivers, creeks and sometimes lakes. + 
-2. Semi-Aquatic Freshwater Crayfish live in burrows connected to water (dams, rivers etc. which are not necessarily permanent) by access shafts and are capable of surviving out of water for long periods. One species, the Chera destructor, as mentioned previously is known by an aboriginal word, "yabby", and inhabits about one third bf Australia. (Refer: map.) +  * "A Salute to the Humble Yabby" by Peter Olszewski. 
-3. Terrestrial FReshwater Crayfish live anywhere on land provided there is water with 2 metres (6 feet) of ground level. +  * "Australian Crustaceans in Colour" by A. Healey & J. Yaldwyn. 
-The Australian Aquatic Freshwater Crayfish - +  * "Australian Freshwater Life" by W. D. Williams. 
-Has several genuses, the main one being the Euastacus (Spiny Freshwater Crayfish). There are +  * "Australian Inland Waters and their Fauna" by A. H. Weatherley. 
-27 species of this genus around Australia, the main ones being:- + 
-1. The Sydney Crayfish. +---- 
-(a) Ebastacus australasiensis which occurs in creeks around Sydney. The young are a muddy +
-brown colour changing through moults to a bright orange in the adults. They grow to about 20 cm (8 inches) from head to tail. +
-(b) EVastacus spinifera which occurs in creeks north of Sydney Harbour. They are usually dark greenish with red markings. +
-2. The Murray Crayfish.  +
-Etastacus armatus is the second largest freshwater crayfish on earth measuring 45 cm +
-(18 inches) from head to tail and is found in the Murray River and many of its tributaries. +
-3. The Laminoton Spiny Crayfish. (Euastacus sulcatus) +
-Is well known to walkers in the beautiful rainforest of the Lamington National Park in +
-south-east Queensland, its only domicile. It is the most spectacular species with bands +
-of bright blue and white with scarlet at its joints. It is sometimes seen walking along +
-the well-graded tracks of the park, hundreds of metres from its creeks in wet weather. +
-When approached it will rear up, waving its large claws and hissing. A threatening sight, +
-even though it only appears to grow to about 22 cm (9 inches) long from head to tail. +
-4. The Gippsland Crayfish - of Victoria. +
-5. The North Queensland Spiny Crayfish. (Euastacus fleckeri) Is found only in the Daintree River and Mossman River areas. +
-SOURCES OF INFORMATION.  +
-"A Salute to the Humble Yabby" by Peter Olszewski. +
-"Australian Crustaceans in Colour" by A. Healey & J. Yaldwyn. +
-"Australian Freshwater Life" by W. D. Williams. +
-"Australian Inland Waters and their Fauna" by A. H. Weatherley. +
-* * * * * * * * * *+
 AUGUST SOCIAL PROGRAM. by Wendy Aliano. AUGUST SOCIAL PROGRAM. by Wendy Aliano.
 19th August. Magazine Wrapping NIght. Come along and help to put the Club magazine 19th August. Magazine Wrapping NIght. Come along and help to put the Club magazine
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 NEEDS, WHETHER NEEDS, WHETHER
 IT BE FOR.... IT BE FOR....
- Bushwalking  Canyoning+ Bushwalking   Canyoning
 O Caving  Skiing O Caving  Skiing
 * Climbing * Climbing
198707.txt · Last modified: 2016/09/16 14:14 by tyreless
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