Monsters in the dark: Systematics and biogeography of the stygobitic genus godzillius (crustacea: Remipedia) from the lucayan archipelago

Remipedia is a stygobitic group commonly associated with coastal anchialine caves. This class consists of 12 genera, ten of which are found within the Lucayan Archipelago. Herein, we describe a new species within the genus Godzillius from Conch Sound Blue Hole, North Andros Island, Bahamas. Godzillius louriei sp. nov. is the third known remipede observed from a subseafloor marine cave, and the first from the Godzilliidae. Remipedes dwell within notoriously difficult to access cave habitats and thus integrative and comprehensive systematic studies at family or genus level are often absent in the literature. In this study, all species of Godzillius are compared using morphological and molecular approaches. Specifically, the feeding appendages of G. louriei sp. nov., G. fuchsi Gonzalez, Singpiel & Schlagner, 2013 and G. robustus Schram, Yager & Emerson, 1986 were examined using scanning electron microscopy (SEM). Species of Godzillius are identified based on the spines of maxilla 1 segment 4 and by the denticles on the lacinia mobilis of the left mandible. A molecular phylogeny using the mitochondrial 16S rRNA and nuclear histone 3 genes recovered G. louriei sp. nov. within the Godzillius clade and 16S genetic distances revealed a 13–15% difference between species of Godzillius

An integrative re-evaluation of Typhlatya shrimp within the karst aquifer of the Yucatan Peninsula, Mexico

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ballou, L., Brankovits, D., Chavez-Solis, E. M., Diaz, J. M. C., Gonzalez, B. C., Rohret, S., Salinas, A., Liu, A., Simoes, N., Alvarez, F., Miglietta, M. P., Iliffe, T. M., & Borda, E. An integrative re-evaluation of Typhlatya shrimp within the karst aquifer of the Yucatan Peninsula, Mexico. Scientific Reports, 12(1), (2022): 5302, https://doi.org/10.1038/s41598-022-08779-9.The Yucatán Peninsula, Mexico is a carbonate platform well-known for extensive karst networks of densely stratified aquifer ecosystems. This aquifer supports diverse anchialine fauna, including species of the globally distributed anchialine shrimp genus Typhlatya (Atyidae). Four species (T. campecheae, T. pearsei, T. dzilamensis and T. mitchelli) are endemic to the Peninsula, of which three are federally listed in Mexico. This first integrative evaluation (i.e., molecular, morphological, broad geographic and type locality sampling, and environmental data) of Yucatán Typhlatya reveals considerable species identity conflict in prior phylogenetic assessments, broad species ranges, syntopy within cave systems and five genetic lineages (of which two are new to science). Despite sampling from the type locality of endangered T. campecheae, specimens (and molecular data) were indistinguishable from vulnerable T. pearsei. Ancestral/divergence reconstructions support convergent evolution of a low-salinity ancestor for a post-Paleogene arc Yucatán + Cuba Typhlatya clade within the anchialine Atyidae clade. A secondary adaptation for the coastal-restricted euryhaline (2–37 psu), Typhlatya dzilamensis (unknown conservation status) was identified, while remaining species lineages were low-salinity (< 5 psu) adapted and found within the meteoric lens of inland and coastal caves. This study demonstrates the need for integrative/interdisciplinary approaches when conducting biodiversity assessments in complex and poorly studied aquifers.Financial support for this study was provided by Texas A&M-CONACYT (TI, FA), TI, FA), PAPIIT IN208519 (DGAPA-UNAM) (FA), CONACYT Ciencia Básica A1-S-32846 (FA), Texas A&M University San Antonio (TAMUSA) Start-up Funds (EB), TAMUSA Research Council Grant (EB), TAMUSA Summer Faculty Grant and Fellowship (EB). NSF-REU/OCE: 1560242 supported AL and EB, and TAMU-Louis Stokes Alliance for Minority Participation (HRD: 1612776) supported SR, LS. This work was also supported by the NSF Graduate Research Fellowship Program (M1703014) and the Cave Conservancy Foundation (LB). Typhlatya sampling was sanctioned under collection permits SEMARNAT/SGPA/DGVS 05263/14, 004471/18, 05996/19

Exploring the Evolution and Biogeographic Distribution of Anchialine Fauna

Anchialine habitats are found within underwater subterranean coastal cave systems and contain a vast array of stygobitic taxa. Due to the inherent difficulties of accessing underwater cave systems, the evolutionary history of many anchialine taxa is not well-known. Anchialine fauna often exhibit globally disjunct distribution patterns that are not readily explained by dispersal or vicariant processes. The objective of this dissertation is to evaluate the evolutionary relationships and distribution within both model crustacean taxa, Remipedia and genus Typhlatya using an integration of ecological, molecular, and morphological evidence to elucidate general biogeographic trends of anchialine fauna. The first study compares the mandibular gnathal edge amongst remipede genera and finds notable disparity amongst the mouthparts, suggesting different feeding strategies may be used across taxa. Additionally, mandibular comparison suggests phylogenetic uncertainty regarding the placement of a few taxa within Remipedia. Using the most comprehensive molecular dataset for Remipedia to date, the second study recovers a phylogeny incongruent with previous studies, suggesting some clades need to be re-examined. The distribution patterns within the class were reassessed to reveal species ranges extending across islands of the same shallow-water banks, but not between banks. This may suggest that deep-water acts as a barrier and potential driver of diversification within select anchialine fauna. The third study compares the interspecies relationships within remipede genus Godzillius, with the inclusion of a description for new species, Godzillius louriei sp. nov. The final study explores the phylogeny and biogeographic distribution of Typhlatya species within the Yucatan Peninsula. This study finds that, contrary to previous marine-colonizing hypotheses, Typhlatya species from the Yucatan may have a fresh/oligohaline ancestor which is hypothesized to have traveled across shallow landspans between the Yucatan Peninsula and Cuba. In summary, these findings suggest that the distribution patterns of anchialine fauna are largely driven by vicariant processes, such as the historic migration of shallow-water platforms. Dispersal may be possible through spelean corridors, but the capabilities and barriers of such migration is likely unique to each taxon and remains a significant question for future research

Fluorescence imaging of tumors in vivo.

We review recent progress in tumor imaging in vivo using fluorescent tags, highlight the problems of fluorescence imaging in small animals, discuss recent advances in near-infrared fluorochromes and quantum dots, and point to some future possibilities. GFP-based fluorescence imaging is briefly discussed. The authors believe that improvements in near-infrared fluorochromes are required to enable practical imaging in tissues at centimeter depths.</p

Noninvasive imaging of quantum dots in mice.

Quantum dots having four different surface coatings were tested for use in in vivo imaging. Localization was successfully monitored by fluorescence imaging of living animals, by necropsy, by frozen tissue sections for optical microscopy, and by electron microscopy, on scales ranging from centimeters to nanometers, using only quantum dots for detection. Circulating half-lives were found to be less than 12 min for amphiphilic poly(acrylic acid), short-chain (750 Da) methoxy-PEG or long-chain (3400 Da) carboxy-PEG quantum dots, but approximately 70 min for long-chain (5000 Da) methoxy-PEG quantum dots. Surface coatings also determined the in vivo localization of the quantum dots. Long-term experiments demonstrated that these quantum dots remain fluorescent after at least four months in vivo.</p

Long-term persistence and spectral blue shifting of quantum dots in vivo.

Quantum dots are a powerful fluorophore family with desirable attributes for fluorescence imaging. They have been used in several animal models with direct clinical relevance, including sentinel lymph node mapping, tracing vasculature and lymphatics, and targeting specific lesions for diagnosis and removal. (1-12) Despite significant interest for use in translational applications, little is known about the persistence and long-term fate of quantum dots in vivo. We have observed fluorescence of quantum dots injected into Balb/c and nude mice for up to two-years post injection using both whole-body and microscopic fluorescence techniques. Two-photon spectral microscopy was used to verify the existence of quantum dots within two-year tissues, but also revealed a range of significantly blue-shifted emission peaks with increased bandwidths. Systemically administered quantum dots persist and retain fluorescence for up to two-years in vivo, but with significantly blue-shifted emission.</p

Sentinel lymph node imaging using quantum dots in mouse tumor models.

We demonstrate that quantum dots injected into two model tumors rapidly migrate to sentinel lymph nodes. PEG-coated quantum dots having terminal carboxyl, amino, or methoxyl groups all migrated from the tumor to surrounding lymph nodes similarly. Passage from the tumor through lymphatics to adjacent nodes could be visualized dynamically through the skin; at least two nodes could usually be defined. Imaging during necropsy confirmed confinement of the quantum dots to the lymphatic system and demonstrated easy tagging of sentinel lymph nodes for pathology. Examination of the sentinel nodes identified by quantum dot localization showed that at least some contained metastatic tumor foci.</p

Monsters in the dark: Systematics and biogeography of the stygobitic genus godzillius (crustacea: Remipedia) from the lucayan archipelago

Remipedia is a stygobitic group commonly associated with coastal anchialine caves. This class consists of 12 genera, ten of which are found within the Lucayan Archipelago. Herein, we describe a new species within the genus Godzillius from Conch Sound Blue Hole, North Andros Island, Bahamas. Godzillius louriei sp. nov. is the third known remipede observed from a subseafloor marine cave, and the first from the Godzilliidae. Remipedes dwell within notoriously difficult to access cave habitats and thus integrative and comprehensive systematic studies at family or genus level are often absent in the literature. In this study, all species of Godzillius are compared using morphological and molecular approaches. Specifically, the feeding appendages of G. louriei sp. nov., G. fuchsi Gonzalez, Singpiel & Schlagner, 2013 and G. robustus Schram, Yager & Emerson, 1986 were examined using scanning electron microscopy (SEM). Species of Godzillius are identified based on the spines of maxilla 1 segment 4 and by the denticles on the lacinia mobilis of the left mandible. A molecular phylogeny using the mitochondrial 16S rRNA and nuclear histone 3 genes recovered G. louriei sp. nov. within the Godzillius clade and 16S genetic distances revealed a 13–15% difference between species of Godzillius

Monsters in the dark: systematics and biogeography of the stygobitic genus Godzillius (Crustacea: Remipedia) from the Lucayan Archipelago

Remipedia is a stygobitic group commonly associated with coastal anchialine caves. This class consists of 12 genera, ten of which are found within the Lucayan Archipelago. Herein, we describe a new species within the genus Godzillius from Conch Sound Blue Hole, North Andros Island, Bahamas. Godzillius louriei sp. nov. is the third known remipede observed from a subseafloor marine cave, and the first from the Godzilliidae. Remipedes dwell within notoriously difficult to access cave habitats and thus integrative and comprehensive systematic studies at family or genus level are often absent in the literature. In this study, all species of Godzillius are compared using morphological and molecular approaches. Specifically, the feeding appendages of G. louriei sp. nov., G. fuchsi Gonzalez, Singpiel & Schlagner, 2013 and G. robustus Schram, Yager & Emerson, 1986 were examined using scanning electron microscopy (SEM). Species of Godzillius are identified based on the spines of maxilla 1 segment 4 and by the denticles on the lacinia mobilis of the left mandible. A molecular phylogeny using the mitochondrial 16S rRNA and nuclear histone 3 genes recovered G. louriei sp. nov. within the Godzillius clade and 16S genetic distances revealed a 13–15% difference between species of Godzillius