The Slender Walker Snail

Kansas is often thought of as a very dry state, a prairie state. Compared to my experiences in Wisconsin, Michigan and Indiana, this is true. That doesn’t mean there aren’t some unique and wonderful wetlands and streams in Kansas that contain unique wildlife. Take for instance the Muscotah Marsh. Located in Atchison County, the marsh is an artesian wetland. Meaning, water is literally coming up out of the ground to create the marsh. I use the name “Muscotah Marsh” to imply a significant sized wetland, but in reality, this is just a tiny little area (Muscotah is the name of the nearest town).

Apart from being the only artesian marsh I’m aware of it Kansas (I’m sure there are more), the marsh is notable for being the home to the only population of slender walker snails in the state (Pomatiopsis lapidaria). Apparently this snail occurs commonly in the eastern U.S. (Pratt 1935), but only isolated population are known from the Kansas-Oklahoma/Great Plains region. However, Liechti (1984) described them as having a spotty occurrence even in the Eastern U.S.

This population of snails is interesting not just because it is so isolated, but because it is so abundant where found. Liechti (1984) found them in densities of 1,255 individuals per square meter (in raised portions of the marsh). Dundee (1957) found a single female could lay 42 eggs after a single mating and all of them would hatch.

Although the Marsh has actually been the subject of research for over a hundred years (see summary in Liechti 1984), there’s been essentially no research done on the site or the snail since the previously mentioned Liechti (1984) paper. In fact, I spoke with Paul on Tuesday about the site, and he wasn’t aware of anyone even visiting the site since he did the paper. In 2003, William Layher submitted a Recovery Plan for the species to KDWP, which was subsequently signed and approved, but this was simply a recounting of other studies. There’s no indicate a new site visit was made, or that the author had even seen the site.

The recovery plan is interesting in its own right. Right now the species is listed as endangered. In order to move from Endangered to Threatened, all that KDWP needs to do is buy or put the land into a conservation easement (the Marsh is currently privately owned). Why this hasn’t been done is beyond me, since getting a species downlisted is the whole point of having a T&E program.

The next part of the recovery plan is the difficult part:

P. lapidaria should be introduced to five sites in various regions of the state. Introductions should be monitored. If the species proliferates and become established in three new locales and persists for five years, the species could be downlisted [from Threatened] to SINC [species in need of conservation] status as events that may impact on site would not affect other sites. If populations continue to flourish for ten years, the species could be removed from all lists.

-- Layher, W.G. 2003. Kansas Recovery Plan for the Slender Walker Snail, Pomatiopsis lapidaria (Say) in Kansas.

This is tough, because introducing species outside of their range is a tricky prospect. Non-indigenous species have turned invasive all over the world. I doubt the Slender Walker Snail poses much threat as an invasive, but what we don’t understand about how species become invasive could fill several books (and has). Probably the entire reason we know as much as we do about the snail is due to its status as a potential intermediate host for Schistosoma japonicum, the human blood fluke, which causes schistosomiasis. The U.S. realized this (and other) species needed to be studied as potential vectors after WWII when soldiers in areas known to contain the fluke started returning state-side.

As I discussed previously, I think many peripheral populations should be conserved, and I think that’s true here too. However, I’m not so confident about introducing them outside their range. Any thoughts?

Sometime before winter, I plan on heading up to try and visit the Muscotah Marsh and see the Slender Walker Snail for myself. I'll be sure to publish pics when/if I get permission to get on-site.

Dundee, D.S. 1957. Aspects of the biology of Pomatiopsis lapidaria (Say). Misc. Publ. Mus. Zool., Univ. Michigan No. 100:1-37.

Liechti, P.M. 1984. Population study of Pomatiopsis lapidaria (Say), a small amphibious snail of endangered status in Kansas. Kansas Biological Survey (KU No. 5054-705). 18 pp.

Pratt, H.S. 1935. A manual of the common invertebrate animals, exclusive of insects. P. Blakiston’s Son and Co., Inc. Philadelphia. Pp. 616-625.

Random Pics

Random snail that I can't identify along the Verdigris River.

Native mussel shells found in the Verdigris River.

American toad (we think) found in the riparian woodlands along the Verdigris River.

Cowskin Creek in southern Sedgwick County. All of the riparian areas were cleared (completely) a year ago.

Why species on the edge should be preserved

Often the political boundaries of states and countries do not align with any biologically relevant boundaries, and so species often occur sporadically or rarely in one state, while being extremely abundant in an adjacent state. These species are considered “peripheral species” and are often derided by developers and biologists alike as being unworthy of special regulatory protection.

Peripheral species often occur in habitat conditions that are not ideal for the species. For instance, many of the peripheral fish species in Kansas are surviving in waters that are almost too saline for the species to survive.

In some cases I tend to agree. Species which are not threatened, when their entire range is considered, should generally not be the focus of threatened and endangered species regulations. However, a number of fairly compelling arguments can be made to support the case that peripheral species deserve more protection than we might at first believe. Biologically, I know of three biological reasons for protecting peripheral species:

1. When species collapse, it appears that populations on the edge are more persistent. This is a counter-intuitive effect, and, in fact, I have no good feeling for why it occurs (in general). Some species may have been intentionally targeted (i.e., sea otters) and therefore it wasn’t profitable to visit peripheral ranges. Other peripheral populations may be isolated, and therefore unaffected by disease or invasive species that are decimating the ‘core’ range. Fraser (1999; the paper which got me thinking about this) compiled a number of examples where both vertebrates and invertebrates became extirpated within the “core” of their range, but persist at the edges. Obviously, if an entire species is at risk, preserving the peripheral populations may be extremely important.

2. Populations at the edge of the species’ range may be reservoirs of important genetic diversity. An example of this could be the Broadhead Skink, a peripheral Kansas species that is more common in Missouri. However, the Broadhead Skink in Kansas may experience hotter and generally more prairie-type conditions. As a result, genes that favor those conditions likely occur more frequently in those populations. Each peripheral population may have different gene frequencies than the core population and other peripheral populations. These populations are each adapted to unique stressors that may become more widespread with environmental changes. For instance, increasing global temperatures are driving many species northward. Those species that will be most likely to lead that forced migration are the ones located in peripheral areas, and having genes that allow them to exploit the new conditions most effectively. Alternatively, if conditions change and no migration is possible, then peripheral species may have the genes necessary for the entire species to survive.

3. Peripheral species may also be endangered elsewhere. For the most part, political boundaries determine the scope of influence for any state or government, but those political boundaries are rarely important biologically. A species endangered throughout its range should also be protected on the periphery of its range.

In addition, there are some more pragmatic reasons to list peripheral species. Listing a species automatically attracts scientific attention to it due to the increased availability of funding and ‘practical application.’ Occasionally, we have discovered a peripheral species occurs much more widely than previously thought (rendering its ‘peripheral’ status obsolete), other times we have learned the species is not as threatened as originally believed.

There is also a considerable amount of eco-tourism that is derived from peripheral species. Birds and mammals in particular attract considerable attention that is substantially focused on areas of high diversity (i.e., transitional landscapes).

I’m not saying this means every peripheral species should be protected, but I am arguing that merely designating a species “peripheral” is not justification to avoid protecting it.

Fraser, D.F. 2000. Species at the edge: the case for listing of “peripheral” species. pp 49-53 in L.M. Darling (ed.) Proceedings of a Conference on the Biology and Management of Species and Habitats at Risk. Kamloops, B.C., Canada.

The Hidden Beauty of the Neosho Midget Crayfish

If there’s a group of animals that gets my complete affection without reservation it is the crayfish. I’m a alum of David Lodge’s lab at the University of Notre Dame, and although David has now moved very strongly into the realm of scientifically informing policy, back in the day he was a huge crayfish guy. Several members of his lab still work pretty exclusively on Orconectes rusticus (the dreaded Rusty Crayfish), and so I spent a lot of my graduate career thinking about crayfish. Plus they are just awesome.

The Neosho Midget Crayfish (Orconectes macrus [Greek, meaning long, in reference to long gonopods]) is a small crayfish found exclusively in the Neosho River Basin, and really almost exclusively in the Spring River Basin (Pflieger 1996). The historic range was probably more extensive, but despite its name, I think it is unlikely this crayfish occurred throughout the greater Neosho River Basin. In Kansas, this species occurs in the Spring River basin, although apparently very rarely. Beasley and Branson (1971) found these crayfish in the Missouri portion of the Spring River, but no where else in the drainage basin. Pflieger (1996) describes the species as “common…in most streams of the Neosho drainage except for North Fork of Spring River in Jasper and Barton counties.” I don’t want to suggest Pflieger is wrong, but if this is accurate, these are the only places on Earth the crayfish is common. Durbian et al. (1994) surveyed crayfish in Cherokee County Kansas (including the Spring River) and found no individuals of this species. Taylor et al. (2004) in their review of Oklahoma crayfish referred to the species as rare or uncommon and did not find it in the Spring or Neosho main-stem. The Kansas Department of Wildlife and Parks did find two individuals in the Spring River in 1996 (Ghedotti 1998), at a location they had been found at historically, but this apparently was the result of considerable sampling effort. More recently, consultants sampling around a power plant in the Spring River collected 12 individuals labeled O. rusticus. Further inspection of a voucher specimen revealed it to be O. macrus (whew!), so the species does still occur in Kansas (KDWP, pers. comm).

The Neosho Midget Crayfish is a Species in Need of Conservation (SINC) in Kansas, which means selling or take of this species are illegal, but does not afford it the kind of protection granted Threatened and Endangered species. For example, projects occurring in the habitat of Neosho Midget Crayfish do not require a Kansas Department of Wildlife and Parks (KDWP) Action Permit. However, KDWP does devote some special consideration to research projects involving SINC species, and we happen to know of a graduate student at Fort Hays State who is conducting a state-wide crayfish survey with some special emphasis on this species (or at least this area).

Like most crayfish, this species is considered to be opportunistic omnivores who will eat decaying vegetation and animal matter, as well as predate on invertebrates and small fish. According to Pflieger (1996) the species behaves more like Cambarus spp. in Missouri than like other Orconectes spp. Having not worked with Cambarus spp. in the past, I’m not really sure what he means, but this species appears to be pretty sedentary, spending most of its time under rocks or in tunnels. According to Pflieger “…not an agile or strong swimmer, and seldom takes evasive action when attempts are made to capture it by hand.” Reproduction apparently occurs in March or early April, and females virtually disappear from sampling collections during April (presumably because they were sequestered in burrows and thus unable to be collected).

The Spring River in Kansas has been the brunt of some fairly severe pollution impacts over the course of its history. The EPA has a 115 mile square Superfund site in this county (see here and here .pdf) from a history of heavy zinc and lead mining, and the Spring River is heavily polluted. Likely due to this pollution history and some fairly extensive development in SE Kansas, a number of species have become endangered or rare from the Spring River drainage. The Neosho Midget Crayfish appears to consist of several isolated populations in tributary streams that are kept disconnected by poor quality habitat in the main-stem of the Neosho and Spring Rivers. In particular, my feeling is that the Spring River in Kansas is a particularly crucial connection between apparently abundant subpopulations in Missouri and isolated populations in Arkansas, Oklahoma and Kansas. Without a strong avenue to re-connect these isolated populations, the entire species is at risk from localized impacts and genetic drift.

Lit cited:

Beasley and Branson. 1971. A partial biological survey of the Spring River drainage in Kansas, Oklahoma, and Missouri Part III. The Crayfishes. Transactions of the Kansas Academy of Science 74:228-233.

Durbian, F.E., B.J. Frey, and D.W. Moore. 1994. Crayfish species from creeks and rivers of Cherokee County, Kansas. Transactions of the Kansas Academy of Science 97:13-17.

Ghedotti, M.J. 1998. An annotated list of the crayfishes of Kansas with first records of Orconectes macrus and Procambarus acutus in Kansas. Transactions of the Kansas Academy of Science 101:54-57.

Pflieger, W.L. 1996. The Crayfishes of Missouri. Missouri Department of Conservation. 152 pp.

Taylor, C.A., S.N. Jones, and E.A. Bergey. 2004. Crayfishes of Oklahoma revisited: New state records and checklist of species. The Southwestern Naturalist 49:250-255.

The Mysterious and Elusive Blackside Darter (Percina maculata)

And with that, Analyze Everything is back. Expect a weekly post on Thursday or Friday, focused initially on Kansas T&E and SINC species. Other posts will pop up sporadically. Hope you enjoy, and feel free to ask questions.

State and federal Threatened and Endangered Species lists are riddled with species who are so rare that they may easily be considered extirpated (or even extinct; see Eskimo Curlew). Although apparently facing no global threat of extinction (even in 1973 the darter was considered endangered in Kansas but not nationally), the Blackside Darter has become a whisper of a ghost in Kansas. According to the NatureServe distribution map (see it here), the existing (or recently existing) Kansas population is confined to the Mill Creek Watershed. This is interesting because the next closest population is in Missouri or Oklahoma, between 4-8 HUC8s away.

During the Summer of 2008, KDWP conducted a survey of the Mill Creek looking for Topeka Shiners (more on them elsewhere). There was some optimism that the Blackside Darter would be found at the same time, since unlike many darters, the Blackside is a common mid-column pool resident (Cross and Collins 1995). At this point, no Blacksides have been found (although some collected specimens may be identified as such later), and as far as I can tell, none have been found in Kansas since 1974! (Drenner and Cross 1981) Actually, now that I dig around the KDWP Stream Survey database I see a record of 3 Blackside Darters found on a site in 1994. A return visit in 2000 didn’t find any, however.

I wonder if the Blackside Darters are becoming extirpated in part due to their hybridization with logperch (P. caprodes). The two species have overlapping ranges, and have been observed to hybridize in Kansas (Drenner and Cross 1981), with hybrids having intermediate physical characteristics. Winn (1958) observed logperch males chasing female P. maculate (the latter being a small portion of the overall darter population even when relatively common). Hybridization may have some weird implications for conservation of rare species (c.f. Perry 2001). I did see a logperch in Mill Creek in July of 2008 that looked ‘funny.’ I wonder if that individual has a Blackside ancestor (might explain why we caught it in a pool).

The Blackside Darter is sexually mature in their second year (Becker 1983), and females may continue breeding until they are 4 years old (Bart and Page 1992). This darter consumes primarily benthic invertebrates (NatureServe 2008), although Cross and Collins (1995) also mentioned that the Blackside Darter “sometimes rises to the surface for food.” Among Kansas darters, the Blackside is unique for not clinging to the stream bottom. In general the species tends to prefer streams that one would consider good for mayfly and stonefly species (i.e., cool, clear streams with moderate currents and gravel substrates). Many Flint Hills streams fit this description, but despite fairly extensive sampling efforts in the Northern Flint Hills (mostly hunting the Topeka Shiner), the species is only known to occur in Mill Creek.

Bart, H. L., Jr., and L. M. Page. 1992. The influence of size and phylogeny on life history variation in North American percids. Pages 553-572 in R. L. Mayden, editor. Systematics, historical ecology, and North American freshwater fishes. Stanford Univ. Press, Stanford, Calfiornia. xxvi + 969 pp.

Becker, G. C. 1983. Fishes of Wisconsin. Univ. Wisconsin Press, Madison. 1052 pp.

Cross, F.B. and J.T. Collins. 1995. Fishes in Kansas. University Press of Kansas, Lawrence KS. p 238.

Drenner, R.W. and F.B. Cross. 1981. A natural hybrid fish, Percina maculate × P. caprodes, from Kansas. Transactions of the Kansas Academy of Sciences 84:61-62.

NatureServe. 2008. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.0. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Accessed: July 21, 2008 ).

Perry, W.L., J.L. Feder, and D.M. Lodge. 2001. Hybridization and introgression between introduced and resident Orconectes crayfishes; implications for conservation. Conservation Biology.

Soil Conservation Commission (SCC). 1973. Rare, Endangered and Extirpated Species in Kansas. I. Fishes. Transactions of the Kansas Academy of Science 76:97-106.