Conservation Biology of Freshwater and : A Compilation Project Emydidaeof the IUCN/SSC — and Freshwaternigrinoda Specialist Group 005.1 A.G.J. Rhodin, P.C.H. Pritchard, P.P. van Dijk, R.A. Saumure, K.A. Buhlmann, and J.B. Iverson, Eds. Chelonian Research Monographs (ISSN 1088-7105) No. 5, doi:10.3854/crm.5.005.nigrinoda.v1.2008 © 2008 by Chelonian Research Foundation • Published 15 May 2008

Graptemys nigrinoda Cagle 1954 – Black-Knobbed Map Turtle, Black-Knobbed Sawback

Em m e t t L. Bl a n k e n s h i p 1, Br i a n P. Bu t t e r f i el d 2, a n d Ja m e s C. Go d w i n 3

1224 Transart Pkwy, Canton, 30114 USA [[email protected]]; 2Department of Biology, Freed-Hardeman University, Henderson, Tennessee 38340 USA [[email protected]]; 3Alabama Natural Heritage Program, Environmental Institute, 1090 S. Donahue Drive, Auburn University, 36849 USA [[email protected]]

Su m m a r y . – The black-knobbed map turtle, Graptemys nigrinoda (Family ), is a medium-sized aquatic turtle of the southeastern United States. It is limited in its range to the Mobile Bay drainages of Alabama and . The turtle prefers large to medium-sized river systems. Little information is available on the habits or life history of this species. The black-knobbed map turtle is listed as Endangered by the state of Mississippi and a Protected Nongame Species by the state of Alabama. The current IUNC Red List Status of G. nigrinoda is Near Threatened, but a revised status of Least Concern is recommended in light of recent surveys in which G. nigrinoda was the most commonly observed and collected species of emydid within its range. Di s t r i b u t i o n . – USA. Restricted to Mobile Bay drainages of Alabama and Mississippi. Sy n o n y m y . – Graptemys nigrinoda Cagle 1954; Graptemys oculifera nigrinoda; Malaclemys nigrinoda. Su b s p ec i e s . – Two recognized: Graptemys nigrinoda nigrinoda (Northern Black-Knobbed Map Turtle) and Graptemys nigrinoda delticola Folkerts and Mount 1969 (Southern Black-Knobbed Map Turtle). St a t u s . – IUCN 2007 Red List: Near Threatened (LR/nt) (assessed 1996, needs updating); CITES: Appendix III (Graptemys spp.; USA); US ESA: Not Listed.

Taxonomy. — The black-knobbed map turtle, to the subspecific designations presented by Folkerts and Graptemys nigrinoda, was described by Cagle (1954). The Mount (1969). Freeman argued that “Folkerts and Mount holotype, Tulane University 14662, is a juvenile female have failed to show that delticola has any clear-cut sets collected from the Black Warrior River, 17.5 miles SSW of of characteristics which are peculiar to the region which it Tuscaloosa, Tuscaloosa County, Alabama. inhabits.” He claimed the authors failed to demonstrate any Two subspecies, the northern black-knobbed map “steps” or breaks in certain morphological features within turtle, G. n. nigrinoda, and the southern black-knobbed the species’ range. Freeman contended that the authors map turtle, G. n. delticola, are recognized (Folkerts and were dealing with an example of geographic variation Mount 1969). Freeman (1970) offered several objections manifested by several north to south clines. Additionally,

Figure 1. Adult male Graptemys nigrinoda from Alabama, USA. Photo by James C. Godwin. 005.2 Conservation Biology of Freshwater Turtles and Tortoises • Chelonian Research Monographs, No. 5

Figure 2. Sexual size dimorphism in Graptemys nigrinoda. Adult female above, adult male below. Photo by James C. Godwin.

Freeman argued that because the range of G. nigrinoda These knob-like projections are often reduced to small, is continuous and the designated zone of intergradation pointed swellings in old females. The posterior marginals is extensive, “it seems improbable that ‘well-defined’ are conspicuously serrate. The pale yellow to yellow-orange geographic races have developed.” Folkerts and Mount plastron is large, unhinged, and has an anterior and posterior (1970) rebutted Freeman’s arguments, and G. nigrinoda has notch (Shoop 1967; Mount 1975; Lahanas 1986). since been considered polytypic by most herpetologists. The carapacial ground color of the northern black- Cagle (1954) stated that the black-knobbed map turtle knobbed map turtle is greenish olive to brown. The median and the yellow-blotched map turtle, G. flavimaculata, are vertebral projections are black. Thin yellow-green, nearly closely related to each other and to the , G. circular rings are present on the pleurals. The rings are oculifera. Cagle believed the three form a unique complex outlined in black and may encircle a dark central smudge ranging from the Pearl River eastward to the Alabama (Lahanas 1986). The lateral portion of the vertebrals River. He suggested that the three species might be placed possess light reticular markings. The dorsal surfaces of the under one ‘superspecific’ designation. However, he also marginals have complete or incomplete light circular lines. reported that the morphological gap between G. nigrinoda The ventral surfaces of the marginals have concentric dark and G. flavimaculata is much greater than that between G. rings at the sutures (Cagle 1954). The plastral ground color flavimaculata and G. oculifera. Cagle suggested that G. is yellowish with narrow dark lines bordering the sutures flavimaculata could perhaps be appropriately listed as a subspecies of G. oculifera. Mertens and Wermuth (1977) considered the three to be subspecifically related. Lamb et al. (1994) identified three distinct monophyletic clades within Graptemys based on analysis of mtDNA. The black-knobbed map turtle was placed within the pseudogeographica clade that also included G. ouachitensis, G. caglei, G. pseudogeographica, G. flavimaculata, G. oculifera, and G. versa. However, relationships within the clade were basically unresolved. Description. — Graptemys nigrinoda is a medium- sized aquatic turtle. Adult females range from 170-220 mm in carapace length and adult males from 70-120 mm (Lahanas 1986). The carapace is moderately domed, possessing a median keel. The first four vertebrals possess median, backward-projecting, knob-like protuberances which arise from the posterior portion of the scute. The Figure 3. Hatchling Graptemys nigrinoda from Alabama, USA. second and third vertebral projections are more pronounced. Photo by James C. Godwin. Emydidae — Graptemys nigrinoda 005.3

Figure 4. Distribution of Graptemys nigrinoda in southeastern USA. Red points = museum and literature occurrence records based on Iverson (1992) plus more recent and authors’ data; green shading = projected distribution based on GIS-defined hydrologic unit compart- ments (HUCs) constructed around verified localities and then adding HUCs that connect known point localities in the same watershed or physiographic region, and similar habitats and elevations as verified HUCs (Buhlmann et al., unpubl. data), and adjusted based on authors’ data.

or with a dark figure occupying not more than 30% of the pattern and coloration similar to adults; however, colors plastral area (Folkerts and Mount 1969). are more vivid and contrasts are greater than in adults. The head is relatively small, olive to brown in color No ontogenetic color changes have been noted except for and has yellow stripes. A pair of yellow postocular crescent- fading coincident with growth and aging. Hatchlings are shaped blotches is present. These blotches are strongly wider than long with pronounced marginal indentations. recurved and usually connected posteriorly to longitudinal The knob-like protuberances on the keel are compressed stripes. The legs and tail also possess longitudinal light laterally. In addition, newly hatched G. nigrinoda have stripes. The soft parts are predominantly light colored with relatively greater plastron and head widths compared to the light stripes wider than the darker greenish-olive to adults, as well as a longer relative post-anal tail length. brown interspaces. The undersurfaces are lighter than the Sexual dimorphism is evident in G. nigrinoda, as in dorsal surfaces (Mount 1975). other species of Graptemys. Lahanas (1982) found 4 of The southern black-knobbed map turtle is similar to 9 morphometric traits to be intersexually different within the nominate subspecies except as follows. A complex G. n. delticola. The most conspicuous sexually dimorphic dark plastral pattern occupies 60% or more of the plastral character is greater size attained by adult females compared area. This plastral pattern may be composed of expanded to adult males. The maximum carapace length reported for a dark lines that follow the seams or may be a central dark female is 221 mm and for a male, 122 mm (Lahanas 1982). figure. The postorbital blotches are not crescent-shaped The seven largest females Lahanas found averaged 200.6 and are not noticeably recurved. These blotches are often ± 5.58 mm CL. The seven largest males averaged 113.0 ± disconnected from the light head stripes. The soft parts of 1.91 mm CL. Females have been shown to have relatively the southern black-knobbed map turtle are predominantly higher shells than males (Folkerts and Mount 1969; Lahanas dark, the dark interspaces being wider than the narrow light 1982). Black-knobbed map turtle males have significantly stripes. The ground color of G. n. delticola is black, unlike longer relative tail lengths than females (Lahanas 1982). the greenish-olive to brown ground color in the nominate Pre-anal tail length was 13.8% of the carapace length for subspecies. The carapace is higher in G. n. delticola than in 28 males and 10.1% for 22 females. Post-anal length for G. n. nigrinoda. males was 22.2% and for females 19.9% (Lahanas 1982). Hatchlings of G. n. delticola were described by When the tail is extended the vent is posterior to the rear Lahanas (1982). Newly hatched turtles exhibit a body margin of the carapace in males and anterior to the rear 005.4 Conservation Biology of Freshwater Turtles and Tortoises • Chelonian Research Monographs, No. 5

margin in females. The foreclaws of adult males are longer and 17 female G. n. delticola in the lower Tensaw River. than those of females (Lahanas 1982). Males have been The males contained 58.3% material and 40.4% shown to have larger hind foot areas, relative to carapace plant material by volume and females contained 69.2% length, than females of similar size. In addition, the angle animal material and 28.1% plant material by volume. of the rear plastral notch is more acute in females than in The three most important animal items consumed were males (Bailey and Folkerts 1987). freshwater sponges, bryozoans, and molluscs. Freshwater The osteology of G. nigrinoda has been described by algae were the only plants consumed. Lahanas (1982) Killebrew (1979), who gave characters that could be used concluded that, although the black-knobbed map turtle to differentiate G. nigrinoda and G. flavimaculata. may occasionally feed at the surface, it is predominantly a Graptemys nigrinoda resembles other Graptemys browser on submerged logs or other submerged objects. in having a prominent keel, knobs, and extensive light Black-knobbed map turtles are seasonally active from striping on soft parts. It can be distinguished from other early April through late November (Lahanas 1982). Basking turtles by the presence of large circular light rings in each may be observed throughout the day with two peak periods of the pleurals and prominent knob-like protuberances of activity, one during mid-morning and another in the on vertebrals one, two, and three. Graptemys oculifera early afternoon (Waters 1974; Lahanas 1982). Hatchlings does not possess prominent knob-like protuberances on have been observed basking on limbs of bushes located the vertebrals. Graptemys flavimaculata has yellowish along river banks and on masses of emergent vegetation to orange blotches within each pleural, normally lacks (J. Dobie, pers. comm.). Basking is unlikely to occur when circular light rings, and lacks prominent knobs on the keel water temperatures fall below 10ºC (Waters 1974). The (Cagle 1954). primary function of basking was believed by Waters (1974) Distribution. — The black-knobbed map turtle is to be thermoregulation. He also provided evidence that found in Alabama below the Fall Line in major streams basking is important in ridding the turtle of ectoparasites, of the Mobile Bay drainage. In Mississippi, it is found in eliminating excessive algal growth on the shell, and in the the Tombigbee River system as far north as Bull Mountain synthesis of Vitamin D. Creek at State Hwy 25, Itawamba county (Cliburn 1970). Males of G. n. delticola reach sexual maturity at 3- It also occurs above the Fall Line in Bankhead Lake, an 4 yrs at a plastron length of about 70 mm; females reach impoundment of the Black Warrior River, in the Locust sexual maturity at 8-9 yrs at a plastron length of about Fork of the Black Warrior River at least as far upstream as 170 mm (Lahanas 1982). Females produce 3 to 4 clutches the mouth of Crooked Creek in Jefferson County, Alabama annually, averaging 5.5 eggs per clutch (Lahanas 1982). (Folkerts and Mount 1969; R. Mount, pers. comm.), and Nesting is nocturnal and occurs from mid-May through on the Coosa River upstream to Mitchell Dam (Godwin early August (observed on Gravine Island, Baldwin Co., 2001). Alabama; Lahanas 1982). Nesting occurs on open expanses Within the range, the nominate subspecies is found of fine sand and nests are located above the water level in the Cahaba, Tallapoosa, and Coosa rivers, and in the within 50 m of shore (Lahanas 1982). Hatching begins in Alabama River downstream approximately to the Wilcox- mid-August after an incubation period of about 62 days Monroe county boundary. Graptemys n. delticola occurs in (Lahanas 1982). freshwater in the Tensaw and Mobile rivers and associated The fish crow, Corvus ossifragus, is a significant waterways, frequently referred to as the upper portion of predator of turtle eggs on Gravine Island (Lahanas 1982), the Mobile Delta. The remainder of the range contains as is the armadillo, Dasypus novemcinctus, and the raccoon, intergradient populations (Folkerts and Mount 1969; Procyon lotor (Godwin 2002). The imported red fire-ant, Mount 1975). Solenopsis invicta, may also be an important predator on Habitat and Ecology. — The black-knobbed map eggs and hatchlings. Dobie (pers. comm.) stated that the turtle occurs in medium- to large-sized rivers and associated imported red fire-ant is probably a significant predator of bayous and oxbows (Mount 1975). Adults and subadults eggs of the black-knobbed map turtle on Gravine Island of delticola prefer main channels, whereas hatchlings and after having found fire-ants in 63 of 79 nest cavities small juveniles are more often found in shallow, sluggish examined. Hatchling and juvenile turtles are thought to be waters of sloughs and bayous if such habitats are available preyed upon by fish, bullfrogs, wading birds, and alligators (Lahanas 1982). Waters (1974) indicated that the availability (Waters 1974; Lahanas 1982). Adults may be prey items for of basking sites is important in determining the areas along a alligators (Waters 1974; Lahanas 1982). Humans are also river the species utilizes. Waters (1974) identified preferred important predators (Waters 1974; Lahanas 1982). Black- basking sites as exposed logs and snags surrounded by open knobbed map turtles are parasitized by leeches externally water. Such sites provide unobstructed views and direct (Waters 1974; Lahanas 1982) and acanthocephalans sunlight for an appreciable portion of the day. internally (Lahanas 1982). Direct observations of foraging behavior have only Population Status. — McCoy and Vogt (1980) provided been reported once. Wahlquist (1970) observed the turtles information on distribution and relative abundance of G. consuming beetles and dragonflies that had fallen into a nigrinoda in Alabama and Mississippi. Their methods included river. Lahanas (1982) examined the gut contents of 15 male both sight survey and trapping using hoop nets. The study Emydidae — Graptemys nigrinoda 005.5

areas consisted of 42 stations distributed across the known Conservation Measures Taken. — The black- range of the species. They determined that the range of G. knobbed map turtle is listed as Endangered by the state of nigrinoda is much larger than that of either G. flavimaculata Mississippi and a Protected Nongame Species by the state or G. oculifera. The area with the greatest abundance of of Alabama. The U.S. Fish and Wildlife Service lists the turtles was in Baldwin County, Alabama, on the Tensaw species as subcategory 3-C (species now considered to be River, from its junction with Middle River to Bryants Upper more abundant or widespread than previously thought). Landing. The Alabama River south of Selma “seemed to be While G. nigrinoda occurs adjacent to conservation particularly depauperate of G. nigrinoda, compared to areas lands, the rivers themselves remain vulnerable. Lands farther north and farther south.” Excellent populations of G. with some level of protection include the Delta Wildlife nigrinoda occur in the Tensaw, Tombigbee, Black Warrior, Management Area of the Mobile-Tensaw Delta, managed Alabama, Cahaba, Coosa, and Tallapoosa rivers. The by the Alabama Department of Conservation and Natural black-knobbed map turtle was the most abundant turtle in Resources, Haines Island, with river frontage on the both basking surveys and spot trapping surveys over much Alabama River, Gravine Island on the Tensaw River, of the range. Large impoundments on the Alabama and both owned by the U.S. Army Corps of Engineers, and Black Warrior rivers did not appear to be detrimental to the the Choctaw National Wildlife Refuge on the Tombigbee species. Channelized areas on the Alabama and Tombigbee River; other protected sites include Ft. Toulouse Historical rivers with heavy barge traffic had fewerG. nigrinoda than Park at the confluence of the Coosa and Tallapoosa rivers. winding areas with moderate current and basking logs. While these sites provide only minimal protection for the The best populations observed were located in relatively rivers, they do provide some minor degree of protection undisturbed areas: the Cahaba River at Sprott, Tombigbee for nesting habitat. The Nature Conservancy owns one River at Rattlesnake Bend, and the feeder streams to the preserve, Bartons Beach, on the Cahaba River. Incidental Tensaw River. All of these areas lack barge traffic, intense protection for G. nigrinoda will be achieved as the Mobile boat use, channelization, or noticeable industrial pollution. Basin Aquatic Ecosystem Recovery Plan (USFWS, 2000) McCoy and Vogt (1980) concluded that: 1) the species is is implemented. The plan addresses the recovery needs doing well at most sites and does not warrant listing as of 22 aquatic species, including the Alabama red-bellied threatened at the present time, and 2) future work should turtle, alabamensis, whose range overlaps with concentrate on determining the habitat differences and that of G. n. delticola, and any recovery measures for P. their causes between areas where the species is abundant, alabamensis that address habitat will be beneficial also to and areas where the species is less common. G. n. delticola. Recent basking surveys for G. nigrinoda and G. pulchra Conservation Measures Proposed. — The current (Godwin 2001, 2003) have supported the prior assessment IUNC Red List Status designation of G. nigrinoda is of McCoy and Vogt (1980). In the Mobile Basin rivers, Near Threatened. A revised status to Least Concern is below the Fall Line, G. nigrinoda was the most commonly recommended in light of the information provided by observed species with an overall average of 15.3 basking McCoy and Vogt (1980) and Godwin (2001, 2003) in turtles/km of river. In contrast, the average for G. pulchra which G. nigrinoda was the most commonly observed and over the same river reaches was 2.3 turtles/km. From 2001 collected species of emydid within its range. An overall to 2003 a total of 224 km of rivers were surveyed in the average of 23.2 basking G. nigrinoda/km of river were range of G. nigrinoda, including reaches on the Alabama, observed compared to an overall average of 3.8 basking G. Black Warrior, Cahaba, Coosa, Tallapoosa, Tensaw, and pulchra/km during surveys in 2001 and 2003. Tombigbee rivers. The species was most abundant on the Captive Husbandry. — The black-knobbed map Alabama and Cahaba rivers, followed by the Tombigbee, turtle has been successfully kept in captivity for research Tensaw, Black Warrior, Coosa, and Tallapoosa. Positively purposes. Waters (1974), while studying the importance of identified males were observed more frequently than basking in G. nigrinoda, successfully held between 10 and females, and all age classes were seen. 20 individuals in a 300 l glass aquarium. A water depth of Threats to Survival. — The black-knobbed map 20 cm was maintained and the water was changed regularly. turtle is potentially threatened by habitat degradation and A basking platform was provided and illuminated by an by direct and indirect persecution by humans. The removal artificial light source. Turtles that were denied a basking of logs (“snagging”) that are used as basking sites may platform soon developed thick growths of algae. Males and be deleterious to this turtle. Alteration and destruction of juveniles thrived without basking for periods of seven to 14 nesting areas and direct interference of nesting females days. However, females not allowed to bask soon developed by humans may also threaten this turtle. Additionally, plastral and carapacial sores. Waters (1974) maintained populations may be impacted from human consumption captive turtles on a diet of ground beef fed twice weekly of turtles and turtle eggs (Lahanas 1982) and vandalistic with lettuce and commercial trout food offered occasionally. shooting of turtles and collecting turtles for the pet trade Mount (1975) stated that captive black-knobbed map turtles (Waters 1974). Commercial fishermen occasionally kill will readily feed on raw liver, chopped fish, and canned turtles caught on trot lines, and turtles also drown in gill dog food. Many freshwater turtles, including G. nigrinoda, nets and hoop nets (Lahanas 1982). will readily accept balanced commercial turtle foods such 005.6 Conservation Biology of Freshwater Turtles and Tortoises • Chelonian Research Monographs, No. 5

as Tetra ReptoMinR with occasional supplementation of Herpetologica 35(2):146-153. insects, worms, slugs, snails, and other invertebrates. La h a n a s , P.N. 1982. Aspects of the life history of the southern Nijs (1999) reported successful reproduction by black-knobbed map, Graptemys nigrinoda delticola Folkerts and Mount. Master’s Thesis, AuburnUniversity, Alabama. captive G. nigrinoda. La h a n a s , P.N. 1986. Graptemys nigrinoda Cagle. Cat. Amer. Current Research. — We are unaware of any research Amphib. Rept. 396.1-396.2. currently being conducted on G. nigrinoda. La m b , T., Ly d e a r d , C., Wa l k e r , R.B., a n d Gi b b o n s , J.W. 1994. Molecular systematics of map turtles (Graptemys): a LITERATURE CITED comparison of mitochondrial restriction site versus sequence data. Syst. Biol. 43(4):543-559. McCo y , C.J. a n d Vo g t , R.C. 1980. Distribution and population Ca g l e , F.R. 1954. Two new species of the Graptemys. Tulane Stud. Zool. 1(11):167-186. status of the black-knobbed map Graptemys nigrinoda Cagle CITES. 2007. Appendices I, II and III valid from 13 September in Alabama and Mississippi. Final Rept. U.S. Fish and Wildlife 2007. www..org/eng/app/index.shtml. Serv. Contract No. 14-16-0004-79-038, 13 pp. Me r t e n s , R. a n d W e r m u t h , H. 1977. Liste der rezenten Amphibien Cl i b u r n , J.W. 1970. The ranges of four species of Graptemys in Mississippi. J. Miss. Acad. Sci. 16:16-19. und Reptilien, Testudines, Crocodylia Rhynchocephalia. Das Tierreich, Berlin, Lieferung 100: 1-174. Ba i l e y , M.A. a n d Fo l k e r t s , G.W. 1987. Sexual dimorphism in the black-knobbed map, Graptemys nigrinoda. J. Ala. Acad. Mo u n t , R.H. 1975. The and Amphibians of Alabama. Sci. 58(3):85. Auburn Univ. Agr. Exp. Sta. Auburn, Alabama, 347 pp. Ni j s , J. 1999. Verzorging en kweek van de Zwartknobbel- Fe d e r a l Re g u l a t i o n . 1989. Endangered and threatened wildlife and plants; animal notice of review. Federal Register 54(4). zaagrugschildpad, Graptemys nigrinoda nigrinoda, in gevangen-schap. Lacerta 57(3): 91-96. Fo l k e r t s , G.W. a n d Mo u n t , R.H. 1969. A new subspecies of the turtle Graptemys nigrinoda Cagle. Copeia 1969(4):677-682. Sh o o p , C.R. 1967. Graptemys nigrinoda in Mississippi. Herpetologica 23(1): 56. Fo l k e r t s , G.W. a n d Mo u n t , R.H. 1970. Reply to H. L. Freeman’s (Herpetol. Rev. 2(1):3) comments on: A new subspecies of the U.S. Fi s h a n d Wi l d l i f e Se r v i c e . 2000. Mobile River Basin turtle Graptemys nigrinoda Cagle. Herpetol. Rev. 2(3):3-4. Aquatic Ecosystem Recovery Plan. Atlanta, GA, 128 pp. Wa h l q u i s t , H. 1970. Maps of the Gulf Coast. Int. Turtle and Fr e e m a n , H.L. 1970. A comment on: A new subspecies of the turtle Graptemys nigrinoda Cagle. By George W. Folkerts Tortoise Soc. J. 4(4):10-13, 28. and Robert H. Mount. 1969. Copeia 1969(4):677-682, 6 figs. Wa l k e r , W.F., Jr. 1973. The locomotor apparatus of Testudines. Herpetol. Rev. 2(1):3. In: Gans, C. and Parsons, T.S. (Eds.). Biology of the Reptilia. IV. Academic Press, New York, pp. 1-100. Go d w i n , J.C. 2001. Black-knobbed sawback (Graptemys nigrinoda) status survey. Unpublished report submitted to the Alabama Wa t e r s , J.C. 1974. The biological significance of the basking Department of Conservation and Natural Resouces, 15 pp. habit in the black-knobbed map, Graptemys nigrinoda Cagle. Master’s Thesis, Auburn University, Alabama. Go d w i n , J.C. 2002. Turtle nest success on Gravine Island with emphasis on the Alabama red-bellied turtle (Pseudemys alabamensis) and Delta map turtle (Graptemys nigrinoda Citation Format for this Account: nigrinoda). Unpublished report submitted to the Alabama Department of Conservation and Natural Resouces, 16 pp. Bl a n k e n s h i p , E.L., Bu t t e r f i e l d , B.P., a n d Go d w i n , J.C. 2008. Graptemys nigrinoda Cagle 1954 – black-knobbed map turtle, Go d w i n , J.C. 2003. Alabama map turtle (Graptemys pulchra) status survey. Unpublished report submitted to the Alabama black-knobbed sawback. In: Rhodin, A.G.J., Pritchard, P.C.H., Department of Conservation and Natural Resouces, 24 pp. van Dijk, P.P., Saumure, R.A., Buhlmann, K.A., and Iverson, Iverson, J.B. 1992. A Revised Checklist with Distribution Maps J.B. (Eds.). Conservation Biology of Freshwater Turtles and of the Turtles of the World. Richmond, IN: Privately Printed, Tortoises: A Compilation Project of the IUCN/SSC Tortoise and 363 pp. Freshwater Turtle Specialist Group. Chelonian Research Mono- graphs No. 5, pp. 005.1-005.6, doi:10.3854/crm.5.005.nigrinoda. Ki l l e b r e w , F.C. 1979. Osteological variation between Graptemys flavimaculata and Graptemys nigrinoda (Testudines: Emydidae). v1.2008, http://www.iucn-tftsg.org/cbftt.