Ambystoma complex

jbherpin

jbherpin

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JBear
I hit the wrong key and apparently lost part 1.... I don't think there is any flesh to chew off my tongue at this point...

Pt. 1:
1: A. laterale- Female(gravid)
2: A. texanum x A. laterale
3: A. laterale- male
4: ?
5: "
6: ?
7:A. laterale-male
8: "

Pt. 2:
1: A. texanum
2: "
3: ?
4: A. texanum x A. jeffersonianum (paratoid glands)
5: "
6: "(gravid)
7: A. texanum x A. laterale
8: A. texanum female(gravid)

Pt. 3:
1: A. texanum x A. laterale
2: "
3: "
4: "
5: "
6: A. laterale x A. jeffersonianum
7: "
8: A. laterale x A. texanum

Pt 4:
1: A. laterale x A. texanum
2: "
3: ?
4: A. laterale- male
5: A. texanum- female
6: ?
7: ?
8: ?

Pt. 5:
1: Chorus Frog(slipped in...) :D
2: ?
3: ?
4: ?
5: ?
6: ?
7: A. texanum x A. laterale
8: "

Something went wrong... I tried to fix it......

JBear
 
Last edited:
Is anyone aware of a good study done on this topic?

I have never discovered a Jefferson Salamander where these were photographed, only A. texanum and A. laterale(and hybrid/intergrades). However, older documentation does not include A. texanum as a member of the hybridization complex, and I am certain they are contributing...

This is not to suggest that A. jefforsonianum are not present... I would love to hear what habitat people encounter them(A. jefforsonianum) in as to have a better understanding of how to survey a potential population. Do they like fallen logs and other such forest debris, are they more commonly encountered under flat stones, or in root structures of tree stumps, etc.?

It could be that these salamanders are simply traveling from outside my study range. Maybe they are not migrating to or through some years as the vernal pool can be very small compared to years where there are tons of larval forms in the water and we had a lot of snow/rain? Any comments would be greatly appreciated.

JBear
NE Ohio resident
 
Saw this today, confirming my beliefs:

Taxonomy:

Kingdom Phylum Class Order Family ANIMALIA CHORDATA AMPHIBIA CAUDATA AMBYSTOMATIDAE
Scientific Name: Ambystoma jeffersonianum Species Authority: (Green, 1827) Common Name(s): English – Jefferson Salamander Synonym(s): Salamandra jeffersoniana Green, 1827

Assessment Information:

Red List Category & Criteria: Least Concern ver 3.1 Year Published: 2004 Date Assessed: 2004-04-30 Annotations: Needs updating
Assessor(s): Geoffrey Hammerson Reviewer(s): Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)

Justification:

Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.

Geographic Range:

Range Description: This species' range was mapped by Conant and Collins (1991) as encompassing an area in the USA from southeastern New York through Pennsylvania and eastern and southern Ohio to southern Indiana, and southward to south-central Kentucky and northern Virginia, with an extensive area of hybridisation with A. laterale northward of this range to eastern Minnesota, northern Wisconsin, Upper Peninsula of Michigan, southern Ontario, southern Quebec, and eastward to Nova Scotia. However, for most of this range, karyological and electrophoretic data are unavailable, so the precise range of pure jeffersonianum populations is uncertain (Bogart and Klemens 1997). The core of the range of pure A. jeffersonianum populations likely extends from Pennsylvania southwestward to Kentucky. The jeffersonianum genome is widely distributed in eastern North America but exists primarily in hybrids (Bogart and Klemens 1997). Individuals that have solely the A. jeffersonianum genome occur in many hybridised populations. Although Klemens (1993) mapped distinct ranges for A. jeffersonianum and A. laterale in Connecticut and adjacent regions, he included in the range of each species populations that were dominated by the pertinent genome, including hybrids. Data presented by Bogart and Klemens (1997) indicate that the few populations in New England and New York represented by only the A. jeffersonianum genome had sample sizes of only 1-3 individuals, so these actually might have been hybrid populations. Phillips (1991) extended the range of A. jeffersonianum into east central Illinois, based on one juvenile raised from a larva, but since only one specimen was examined (and he did not indicate what identification criteria were used), it is unclear whether or not the population represents pure A. jeffersonianum or a hybrid population. Phillips et al. (1999) indicated the occurrence of both pure A. jeffersonianum and hybridised A. jeffersonianum ("A. platineum") in east central Illinois, and they stated that the hybrids use A. texanum sperm to activate egg development. In northern New Jersey, Nyman et al. (1988) found that triploid hybrids apparently occur wherever A. jeffersonianum is found. In Indiana and Ohio, jeffersonianum genomes exist in hybridised individuals that also contain A. texanum and/or A. tigrinum genomes (Morris 1985, Morris and Brandon 1984,Selander et al. 1993, Selander 1994).

Countries: Native:

Canada; United States


Reference: www.iucnredlist.org

JBear
 
Have any Ohio, Michigan, Minnesota,(or any Northern, state) New Englanders seen hybridization? I have many pics of representatives... If you google these species you will see many forms pictured with the majority being intergrades/hybrids. Very few pure forms are represented online. Should this be a concern as the intergrades/hybrids are all female? If the populations become female heavy, isn't that an indicator of a potential die off/die out in time. If the species in question continue to interbreed and create solely female offspring wouldn't the pure forms be at a genetic disadvantage? Isn't this worth exploring? The way I see it the pure forms will die off before the all female hybrids resulting in an all female populous which would in turn result in pure form extinction. Do I have this wrong? Thank You!

JBear
 
Giving this a little bump...

JBear
 
jbherpin said:
Is anyone aware of a good study done on this topic?

I have never discovered a Jefferson Salamander where these were photographed, only A. texanum and A. laterale(and hybrid/intergrades). However, older documentation does not include A. texanum as a member of the hybridization complex, and I am certain they are contributing...

This is not to suggest that A. jefforsonianum are not present... I would love to hear what habitat people encounter them(A. jefforsonianum) in as to have a better understanding of how to survey a potential population. Do they like fallen logs and other such forest debris, are they more commonly encountered under flat stones, or in root structures of tree stumps, etc.?

It could be that these salamanders are simply traveling from outside my study range. Maybe they are not migrating to or through some years as the vernal pool can be very small compared to years where there are tons of larval forms in the water and we had a lot of snow/rain? Any comments would be greatly appreciated.

JBear
NE Ohio resident
Click to expand...

Ooooooo this is a research topic I've been super interested in recently. Ambystomatids and urodeles in general are genetic weirdos, luv it. I'd suggest Googling kleptogenesis in the unisexual Ambystoma complex if you haven't already. (Off topic but also crazy: salamander "giant genomes" and their implications)
I'm not sure what you mean by 'posing a threat', as I'm fairly certain this is a well-established phenomenon. ("All unisexuals share a common mitochondrial genome and are thought to have arisen from a single hybridization event 5 million years ago." - Charney et al. 2014 citing Spolsky et al., 1992; Bi and Bogart, 2010)

With regards to the hybrid types in your area, here's a paper addressing just that (also the one I just referenced). You should be able to access it for free: https://www.researchgate.net/public...tributions_in_the_Unisexual_Ambystoma_Complex

Katy Greenwald at Eastern Michigan University is one researcher I know off-hand whose research focuses on the unisexual Ambystoma complex.

Eastern Michigan University: Biology

She's also very active on Twitter and I'm sure more than willing to answer what questions you may have!

https://twitter.com/amphibs

I hope this helps to start you off and is what you were looking for! Happy researching!

Harly
 
Thank you so much for the information and the interest! I simply find it fascinating...

JBear
 
There's no threat. The sources mentioned are an excellent start. These are not hybrids in the usual sense, but a newer concept called "kleptogens". The two main kleptogens, formerly "A.tremblayi" and "A.platineum" arose in part from a probably extinct species, and occur in many regions where one of the "parental" species is entirely absent. In fact, the kleptogens, when they interbreed with other forms, are capable of producing offspring which are in effect various 'pure' species, current kleptogens, or new combinations.

The two simple, main forms are capable of producing only two possible kinds of offspring each: "A.tremblayi" is all-female, and interbreeds primarily with A.laterale. It only produces female "A.tremblayi" or either gender of A.laterale as offspring. It's not possible for it to produce A.jeffersonianum, as that would require two sets of A.jeffersonianum chromosomes, which are never available. Likewise, "A.platineum" is all-female and interbreeds primarily with A.jeffersonianum to produce A.jeffersonianum and "A.platineum". No A.laterale are possible. These kleptogens can only occur in the presence of males of a pure species, generally one of the ancestral species, and since they have no males of their own, and can produce pure animals of both genders of the pure species, they cannot possibly be a threat to any species.
 
Thank you for your interest and your help! Older books made it sound like these "hybrids" were a sort of genetic dead end. Also suggested that the "hybrids" outnumbered pure forms. This is what led me to speculate that over time pure forms would face a marked decline in population. Thank you for the explanation.

I was thrilled to find a population of A. laterale locally. In all distribution maps I have seen, A. laterale as a pure form, has never been documented anywhere in Ohio with the exception of the extreme NW. I am just West of Cleveland(45 minutes). I have reported my findings to my division of natural resources along with pictures. Sadly there was little interest shown, despite that A. laterale is classed as 'endangered' in the state of Ohio.

JBear
 
Kleptogens with a single set of A.laterale chromosomes [ie, mainly "A.platineum"] interbreed with male A.jeffersonianum and can produce both "A.platineum" and A.jeffersonianum as offspring, and they can occur far outside the range of A.laterale, but always with A.jeffersonianum. They carry A.laterale chromosomes but cannot produce A.laterale, and do not need to co-occur with it. This is essentially the reverse or counterpart of "A.tremblayi".

These four forms are the main ones historically recognized. With the addition of three other species interbreeding, and up to 5 sets of chromosomes present, there are something like 30 possible chromosome combinations additional to the pure species, so diagnosing which of the 5 species and 30-some-odd variants you might have, especially in Ohio, would be essentially impossible in some places. In many places though, only one pure parental species occurs (plus A.tigrinum, which is rarely involved). In MN, only A.laterale is known. The couple of kleptogens confirmed implies that they must be present in some numbers across the northeast, as A.jeffersonianum chromosomes cannot magically appear without parents to provide them.
 
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