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| Lacunicambarus dalyae
Glon, Williams & Loughman, 2019
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Abstract
The Jewel Mudbug, Lacunicambarus dalyae sp. nov., is a large, colorful primary burrowing crayfish found in Alabama, Florida, Georgia, Mississippi and Tennessee. This species is most similar in appearance to the Paintedhand Mudbug, L. polychromatus, a species found across the Midwestern United States. The ranges of the two species overlap minimally, and they can be distinguished from each other based on several characters, the most notable of which is the much longer central projection of the gonopod in Form I and II males of L. dalyae sp. nov. relative to L. polychromatus. Like its congeners, L. dalyae sp. nov. is commonly found in burrows in the banks and floodplains of streams and is resilient to a moderate amount of anthropogenic habitat degradation, being occasionally collected from burrows in roadside ditches and urban lawns.
Key words: polychromatus, diogenes, paintedhand mudbug, devil crayfish, jewel mudbug, taxonomy, systematics
Taxonomy:
Family Cambaridae Hobbs 1942
Genus Lacunicambarus (Hobbs, 1969)
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| Dorsal view of Form I holotypic male of Lacunicambarus dalyae sp. nov. (OSUMC 10855). |
Lacunicambarus dalyae Glon, Williams and Loughman sp. nov.
Diagnosis. Eyes pigmented, not reduced. Rostrum narrow, moderately deflected, curving downward in lateral view, margins moderately thickened to acumen, lacking marginal spines or tubercles and median carina, shallowly excavated. Acumen distinctly delimited basally by 45° angles. Cephalothorax subcylindrical, laterally compressed, with 1–10 (mean: 6) adpressed tubercles lining posterior margin of cervical groove. Suborbital angle acute. Postorbital ridges developed, ending cephalically in small tubercle. Areola obliterated, constituting in adults 40–45% (mean: 42%) of entire length of cephalothorax. Antennal scale 2.7 to 3.6 (mean: 3.0 ) times as long as wide, broadest at mid-length, antennal spine strongly developed. Dorsomesial 1/4–1/3 surface of palm of chela studded with distinct to adpressed tubercles, mesial-most row consisting of 6–9 (mean: 8). Opposable margin of dactyl with concavity just proximal to midpoint. Ratio of dactyl length to palm length 1.6–2.0 (mean: 1.8). Dorsomesial longitudinal ridges of dactyl and propodus weakly developed. Dorsolateral impression at base of propodus weak. Ventral surface of chela with 0–7 (mean: 1) subpalmar tubercles. Mesial ramus of uropod with distomesial spine not reaching caudal margin. Gonopods of Form I males contiguous at base, with pronounced umbo near mid-length of caudal surface; terminal elements consisting of 1) long central projection lacking subapical notch, slightly tapered at mid-length, distally rounded, slightly shorter than mesial process, directed caudally at approximately 90o , overreaching margin of umbo by noticeable amount, 2) long mesial process with conical base, tapering slightly near mid-length, tipped with protruding finger, directed caudally at approximately 90o and overreaching margin of umbo by noticeable amount, 3) inconspicuous caudal knob protruding from caudolateral base of central projection. Hook on ischium of third pereiopod only. Female with annulus ventralis subcircular or subquadrangular, slightly wider than long, deeply embedded in sternum, with anterior half mildly pliable and posterior half sclerotized.
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Type locality. We collected the holotype and allotype from the banks of Big Richland Creek, a tributary of the Tennessee River in Humphreys County, Tennessee. Most of the burrows at this site were within 1 meter of the stream channel and relatively shallow. These burrows were surrounded by dense ground vegetation and occasional young trees. The soil at this site was primarily clay mixed with a small amount of sand and pebbles.
We collected the morphotype and paratypes from burrows in and above the floodplain of Hurricane Creek, a tributary to the Duck River in Humphreys County, Tennessee. The burrows that we excavated at this site were up to 10 m away from the stream channel and surrounded by ground vegetation (including a large amount of poison ivy) and mature trees. The terrain beyond the floodplain of Hurricane Creek at this site is steeply sloped causing some burrow entrances to be over 2 m above the water table and therefore particularly difficult to collect crayfishes from. The soil at this site was mostly clay loam with some sand.
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Crayfish associates. Given that L. dalyae sp. nov. is broadly distributed across the most crayfish species-rich region of the world, an exhaustive list of crayfish associates would be intractable. Adults of burrowing crayfish species like L. dalyae sp. nov. often live in clustered colonies (Clay et al., 2017), but multiple burrowing crayfish species may also live in close proximity to one another in partially or completely overlapping colonies. For instance, we have collected C. gentryi Hobbs, 1970 and C. striatus Hay, 1902 from burrows directly adjacent to those of L. dalyae sp. nov. in Tennessee. Colleagues of ours have collected L. dalyae sp. nov. and its congener L. aff. diogenes from numerous sites in Mississippi and Florida (Susie Adams & Paul Moler, personal communication). Similarly, Miller et al., 2014 reported collecting Creaserinus fodiens (Cottle, 1863), C. striatus, C. latimanus (Le Conte, 1856), and Procambarus acutissimus (Girard, 1852) from burrows in the vicinity of L. dalyae sp. nov. burrows in Alabama. In short, a large number of southeastern primary or secondary burrowing crayfishes could be found occurring in sympatry with L. dalyae sp. nov. so long as the habitat is suitable.
Etymology. It is with great pleasure that we name this crayfish after Dr. Marymegan Daly, a Professor in the Department of Evolution, Ecology, and Organismal Biology and Director of the Museum of Biological Diversity at The Ohio State University. It is thanks to the opportunity presented by Dr. Daly to the lead author to join her lab, as well as her continued guidance and instruction on topics such as zoological nomenclature and systematics, that the recent revisionary work on Lacunicambarus was ever undertaken. Dr. Daly is an accomplished invertebrate zoologist and systematist who has greatly advanced her field during her ongoing career and is also a thoughtful and caring person who strives for equality and justice in this turbulent world. The crayfish described herein does not possess nematocysts, but we trust that Dr. Daly will be captivated by it all the same!
We suggest the common name “Jewel Mudbug” for this species as a testament to its magnificent color pattern. This crayfish’s golden background color and polychromatic highlights gives the impression that it has been cast in gold and adorned with precious stones. We refer to this crayfish as a mudbug to denote that it is a primary burrowing crayfish.
Mael G. Glon, Bronwyn W. Williams and Zachary J. Loughman. 2019. Lacunicambarus dalyae: A New Species of Burrowing Crayfish (Decapoda: Cambaridae) from the southeastern United States. Zootaxa. 4683(3); 361–380. DOI: 10.11646/zootaxa.4683.3.3
