Spinastacoidies Spp. A review of the litrature.

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This is a paper i wrote on Spinastacoidies crayfish of Tasmania. Sorry about the missing images, for anyone who would like the images please email me and i will send you a pdf of the full paper. eldhamud at gmail dot com.Introduction First described as Parastaciodes sp, by Clark in 1936, Spinastacoidies sp, has undergone a number of revisions since it was first classified. Having been revised by Riek (1969), Summer (1978) , Hanson (2001) before being redescribed as Spinastacoidies spp by Hanson et al., (2006). Spinastacoidies consists of 1 species with three subspecies P. inermis, P. insignis and P. cantinipalmus. The name Spinastacoidies means “spiny crayfish” is derived from the Latin spina meaning spine and astacoides meaning crayfish like they are rarely more than 80mm in length, with antennae as long as the carapace. Fig 2: Schematic of Spinastacoidies uropod endopod showing terminal spines. (Hanson and Richardson 2006 )The defining feature of this species are the uropod endopod terminal spines (Fig 2). These burrowing crayfish have highly restricted geographical distributions, form symbiotic relationships with plant species and occupy different environmental niches often only meters apart from each other (Hanson and Richardson 2002). They are also considered to be a keystone species within these habitats because of the fundamental roll they play within the ecosystem (Driessen 2006). Spinastacoidies has a life cycle that is typical of many Australian crayfish species (Hamr 1992, Hamr and Richardson 1994) and have a two year reproduction cycle in which the eggs are carried by the female over winter and the hatchings stay connected to the mother till March the following year (Hamr 1994). The rugged an inaccessible nature of the terrain in which Spinastacoidies inhabits has been a limiting factor in the amount of research that has been conducted on this species. This has also protected it from threats to its environment from humans in the form of logging, agriculture and water degradation as well as threats from invasive species like the mainland yabby (Cherax spp.).Geographic Range Spinastacoidies has a very limited range restricted to the southwestern corner of Tasmania. The species distribution is bounded in the north by Lake St Clair, in the east by the 1000mm isohyet known as the Tyler Line and in the south by the coast. Tyler Line corresponds with a sharp change in environmental gradient which reflects geological, edaphic and climatic changes and this eastern boundary closely approximates the east west climatic gradient across Tasmania where evaporation exceeds rainfall during the summer months. (Hanson and Richardson 2002, Richardson et al, 2002)Fig 3: Geographical distribution of S. inermis. (Hanson and Richardson 2006, 2002, Richardson et al, 2002)Each of the 3 subspecies of Spinastacoidies have highly restricted distributions within this geographical area. S. inermis has been recorded in the Arthur, Catamaran, Crossing, Davey, D'Entrecasteaurx, Esperance, Huon, Lune, Moth, New, Picton, South Cape, Salisbury and Weld river, stream and Fig 4: Geographical distribution of S. insignis. (Hanson and Richardson 2006, 2002, Richardson et al, 2002 )catchment areas (Fig 3). S. insignis has been recorded in the following river, stream and catchment systems, Coffin, Cracroft, Davey, De Witt, Frankland, Fulton, Giblin, Gordon, Hardwood, Huon, Melaleuca, Moth, Mulcahy, North, Olga, Passage, Spring, Race, Wanderer and White House (Fig 4). Fig 5: Geographical distribution of S. cantinipalmus. (Hanson and Richardson 2006, 2002, Richardson et al, 2002 )S. cantinipalmus is limited to the following river, stream and catchment areas, Albert, Andrew, Baxter, Bird, Davey, Derwent, Franklin, Gell, Gordon, Hardwood, Hibbs, Jane, King, Maxwell, Nora, Olga, Orange, Pokana and Wanderer. (Fig 5)Habitat Requirements SpeciesBurrow TypesLocationSubstrateVegetation TypeS. inermis1a, 1b, 2Swamps, slopes, seepages, lakes, creeksPeats, clays, muds, gravelGraminiod heaths, rainforest, wet sclerophyll forest, moss, coastal and alpine S. insignis1a, 1b, 2Slopes, ridges, plains, swamps, seepages and creeksPeats, sands, muds gravelGraminiod heath, Melaleuca scrub, wet sclerophyll forest, coastal and alpineS. cantinipalmus1a, 1b, 2Seepages, lakes, creeksPeats, sands, muds gravelGraminiod heath, Melaleuca scrub, wet sclerophyll forest, mossTable 1: Habitat characteristics of Spinastacoidies sp. (Hanson and Richardson 2006, 2002, Richardson et al, 2002 , Growns and Richardson 1988, Horwitz and Richardson 1986, Richardson and Swain 1980 )The distribution of Spinastacoidies covers a wide range of different and varied habitats. Richardson and Swain (1980) claimed the three species occupy more or less distinct habitats however there seems to be a lot of overlap between each species as well as some habitat partitioning (Hanson and Richardson 2002) even tho they occupy distinct geographical regions. Fig 6: Buttongrass moorland habitat, inhabited by Spinastacoidies. (© Launceston Environment Center )(Hanson and Richardson 2006, 2002). Spinastacoidies seems to prefer nutrient poor, low Ph, water logged soils and anoxic environments or sedgeland heaths and peat bogs where is has developed a symbiotic relationship with the moorland buttongrass, Gymnoschoenus sphaerocephalu (Growns and Richardson 1988, Richardson 1990, Driessen 2006). , However it can also be found in many other habitat types, which is likely due to habitat partitioning, where the presents of one species in an area restricts another species from utilizing this territory (Hanson and Richardson 2002). Within the sedgeland heath environments Spinastacoidies reaches its highest population densities. Fig 7: Wet sclerophyll forest habitat, inhabited by Spinastacoidies. ( © Launceston Environment Center )Burrows Spinastacoidies burrows serve a number of functions, shelter from extremes in environmental conditions, an environment for mating and brooding, water to moisten gills, a source of food in the forms of roots in blind chambers, detritus and invertebrates that enters the burrow system. Horwitz and Richardson (1986) proposed a system by which to classify the burrows of Australian crayfish based on a the system proposed by Hobbs (1981) using location of the burrow and their connectedness with water as the delimiting factors. Table 1 shows that Spinastacoidies, use type 1a, 1b and type 2 burrow systems. Type 1a burrows are found in permanent bodies of water like lakes, creeks and rivers. They can be found under rocks, submerged logs or between rock crevices. These Fig 8: Schematic showing morphological structure of burrows used by Spinastacoidies spp. B. blind chamber, F. fringe roots, G. buttongrass tussock, P. burrow opening, Q. quartzite bedrock, T. terminal chamber (Growns and Richardson 1988).burrows are short and unbranched and used mostly for shelter. These are the simplest burrow systems used by Spinastacoidies (Horwitz and Richardson 1986). Type 1b burrows are more complex systems found in the banks of permanent waters. They contain entrances both above and below the mean water level and are extensively branched (Horwitz and Richardson 1986). In type 2 burrows there is no direct connection to surface water. Spinastacoidies in this instance burrows down to the water table where they receive seasonal surface run off, lateral percolation of water from the soil profile as well as from the rise and fall of the water table itself (Horwitz and Richardson 1986).Fig 9: Schematic diagram showing position of burrow types in relation to topography. (© Launceston Environment Center )The blind chambers of Spinastacoidies burrows are important for feeding, situated under the roots of G. sphaerocephalu which forms a large part of their diet. Spinastacoidies spends most of its time foraging within its burrow system. Larger animals occupy burrows of larger volume that contain more blind chambers (Lake 1975, Growns 1988). The terminal chamber is a water filled area of the burrows where mating and birth occurs. It is the lowest part of the burrow system, generally located on the underlaying bedrock. (Lake 1975, Growns 1988).Diet Spinastacoidies is an omnivorous detritus feeder, where plant material makes up the majority of its diet (Lake and Newcombe 1975). Further investigation by Growns and Richardson (1988) uncovered the full extent of the diet of Spinastacoidies by examining the contents of their stomaches and categorizing the contents as either detritus, Gymnoschoenus, roots algae and animal. What Growns and Richardson (1988) found was that Spinastacoidies diet consisted of around 80% detritus through out the year with varying amounts of the other components, of which animal was the next highest with a maximum of 15% and the other 3 categories were only ever found in trace amounts. While Spinastacoidies forms a symbiotic relationship with Gymnoschoenus, it primary gain is not feeding on root fragments in the blind chambers, it would seem that the gain is in the form of leaf detritus that falls and enters the burrow system. ReferencesDriessen . M., (2006). The fauna of buttongrass moorland. The Tasmanian Naturalist 128: 37-51Growns, I.O., and Richardson, A.M.M., (1988). Diet and burrowing habits of the freshwater crayfish, Parastacoides tasmanicus tasmanicus Clark (Decapoda : Parastacidae). Australian Journal of Marine and Freshwater Research 39, 525–534.Hamr, P (1992). Embryonic and postembryonic development in the Tasman freshwater crayfishes Astacopsis gouldi, Asatcopisis franklinni and Parastacoides tasmanicus tasmanicus (Decapoda : Parastacidae). Australian Journal of Marine and Freshwater Research 43, 861–878. Hamr, P and Richardson, A (1994). Life history of Parastacoides tasmanicus tasmanicus Clark, a burrowing freshwater crayfish from south-western Tasmania . Australian Journal of Marine and Freshwater Research 45, 455–470.Hansen B., Richardson A.M.M. (2006). A revision of the Tasmanian endemic freshwater crayfish genus Parastacoides (Crustacea : Decapoda : Parastacidae). Invertebrate Systematics 20, 713–769. Hansen B., Richardson A. M. M. (2002). Geographic ranges, sympatry and the influence of environmental factors on the distribution of species of an endemic Tasmanian freshwater crayfish. Invertebrate Systematics 16, 621–629. Hansen B., Adams M., Krasnicki T., Richardson A. M. M. (2001). Substantial allozyme diversity in the freshwater crayfish Parastacoides tasmanicus supports extensive cryptic speciation. Invertebrate Taxonomy 15, 667–679. Hansen B., Richardson A.M.M. (2006). A revision of the Tasmanian endemic freshwater crayfish genus Parastacoides (Crustacea : Decapoda : Parastacidae). Invertebrate Systematics 20, 713–769. Hobbs, H.H., (1981). The Crayfishes of Georgia. Smithsonian contributions to zoology. 318, 1-549.Horwitz, PHJ and Richardson, AMM (1986). An ecological classification of the burrows of Australian freshwater crayfish. Australian Journal of Marine and Freshwater Research 37, 237–242. Lake, P.S., Newcombe, K.J. (1975). Observations on the ecology of the crayfish Parastacoides tasmanicus (Decapoda; Parastacidae) from south-western Tasmania. Australian Zoologist 18, 197-213.Launceston Environment Center 34 Cameron Street Launceston TAS 7250 Richardson, A., (1990). The implications of vegetation change for animals and their habitats. Tasforests, 173-178.Richardson, A.M.M., and Swain, R. (1980). Habitat requirements and distribution of Engaeus cisternarius and three subspecies of Parastacoides tasmanicus (Decapoda : Parastacidae), burrowing crayfish from an area of south-western Tasmania. Australian Journal of Marine and Freshwater Research 31, 475–484. Richardson, A., Doran, N. and Hansen, B. (2006). The geographic ranges of Tasmanian crayfish: extent and pattern. Freshwater Crayfish 15: 347-364. Riek, EF (1967). The Tasmanian freshwater crayfish genus Parastacoidea (Decapoda : Parastacidae). Australian Journal of Zoology 15, 999–1006. Sumner, CE (1978). A revision of the genus Parastacoides Clark (Crustacea : Decapoda : Parastacidae). Australian Journal of Zoology 26, 809–821.