Browsing by Author "Sparks, John S."
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Item A new extinct species of Malagodon (Cyprinodontiformes: Pantanodontidae) from southeastern coastal Madagascar : with a discussion of its phylogenetic relationships and a redescription of the genus (American Museum novitates, no. 4012)(American Museum of Natural History., 2024-04-24) Carr, Emily M.; Martin, Rene P.; Sparks, John S.A new species belonging to the recently described genus Malagodon Meinema and Huber, 2023, is herein described from specimens collected in a single, small, isolated Pandanas swamp in southeastern coastal Madagascar, located within the Réserve Spéciale de Manombo, south of the town of Farafangana, its only known locality. The new species was last collected in the late 1990s, and despite repeated attempts over the past three decades, no additional specimens have been collected at the type locality or from any other suitable habitats within the region, and the species is presumed to be extinct. The new species is distinguished from its only congener, Malagodon madagascariensis, formerly known from forested swamps in northeastern coastal Madagascar, and also now considered to be extinct, by the following apomorphic features: a lower anal-fin ray count (15–17 vs. 18–19), a longer caudal peduncle (26.8%–39.8% vs. 21.9%–26.7% SL), and the presence of a platelike (vs. thin and spinelike) neural spine on the fifth vertebral centrum in both sexes. Additionally, the new species exhibits neural spines on both the sixth and seventh vertebral centra that are also somewhat expanded and platelike dorsally compared with those in M. madagascariensis, which are narrow and spinelike. We also provide a rediagnosis of Malagodon based on the examination of additional material unavailable in the original description, which was based on only three specimens (two males of M. madagascariensis and one female of the new species).Item A clade of non-sexually dimorphic ponyfishes (Teleostei, Perciformes, Leiognathidae) : phylogeny, taxonomy, and description of a new species. American Museum novitates ; no. 3459(New York, NY : American Museum of Natural History, 2004) Sparks, John S.; Dunlap, Paul Vernon.A phylogeny was generated for Leiognathidae, commonly known as ponyfishes, using nucleotide characters from two mitochondrial genes. Results indicate that Leiognathidae comprises two major clades, one consisting of species that exhibit internally sexually dimorphic light-organ systems (LOS), and the Leiognathus equulus species complex, whose members exhibit neither internal nor external sexual dimorphism of the LOS. Species with internally sexually dimorphic LOS generally also exhibit associated male-specific external modifications in the form of transparent patches on the margin of the opercle, the midlateral flank, or behindthe pectoral fin axil. The L. equulus species complex is the sister group to all other leiognathids, and a new species, L. robustus, recovered within this clade is described herein. Results demonstrate that Leiognathus is paraphyletic, whereas Gazza and Secutor are each monophyletic and are nested within the sexually dimorphic clade. The morphology of the LOS of nonsexually dimorphic leiognathids is compared to the more common sexually dimorphic state, and differences in these systems are discussed and illustrated. In the context of a family-level phylogeny, we can trace the evolution of the leiognathid LOS from a 'simple' non-sexually dimorphic circumesophageal light organ to a complex and species-specific luminescence system involving not only major structural modifications of the light organ itself but also numerous associated tissues.Item Description of a new species of ponyfish (Teleostei, Leiognathidae, Equulitini, Photolateralis) from the Gulf of Oman. (American Museum novitates, no. 3929)(American Museum of Natural History., 2019-06-19) Sparks, John S.; Chakrabarty, Prosanta.A new species belonging to the leiognathid genus Photolateralis, collected from the coastal waters of Oman, is described herein. Photolateralis is unique among leiognathid genera in possessing a species-specific translucent midlateral flank stripe that may be comprised of either multiple independent translucent windows (P. stercorarius, P. moretoniensis, and the new species) or a continuous translucent lateral band (P. antongil). Photolateralis polyfenestrus, new species, is distinguished from congeners by the presence of a short, composite midlateral stripe comprised of three small, rounded translucent windows (vs. numerous windows in both P. stercorarius and P. moretoniensis, or a continuous translucent stripe in P. antongil), and that is confined to the midflank (vs. extending a majority of the length of the flank in congeners). The new species is further distinguished from both P. moretoniensis and P. antongil by a shallower body, and from both P. stercorarius and P. moretoniensis by a pigmentation pattern above the lateral midline comprised primarily of larger rounded blotches (vs. smaller sinuous lines and markings comprising a vermiculated pattern). Photolateralis polyfenestrus is characterized by a lower jaw that is deep and convex in lateral view (vs. mostly straight in congeners, excluding P. antongil), and that forms an angle of between 60°-70° to horizontal (vs. less than 45° in congeners, excluding P. antongil). The only other species of Photolateralis reported from the western Indian Ocean is P. antongil, to date only known from the coastal waters of Madagascar, whereas both P. stercorarius and P. moretoniensis have ranges restricted to the western Pacific and extending into the eastern Indian Ocean.Item Description of a new species of rariphotic Parapercis (Perciformes: Pinguipedidae) from the Solomon Islands (American Museum novitates, no. 3978)(American Museum of Natural History., 2021-09-30) Sparks, John S.; Chaloux, Nicholas; Schelly, Robert C.; Gruber, David F.; Sparks, Tate S.; Phillips, Brennan T.A new species belonging to the pinguipedid genus Parapercis is described herein from a single specimen collected via a remotely operated vehicle (ROV) from rariphotic depths in the Western Province of the Solomon Islands. Parapercis rota, new species, is readily distinguished from all other congeners by a unique pigmentation pattern comprising four large, rounded, orangish-olive saddles dorsally on the flank, each with a distinct, large, dorsomedial white spot completely enclosed within the saddles, plus a fifth saddle on the caudal peduncle with only a small white dorsomedial dot; 10 discrete broad, dark orangish-olive oval vertical bars below the lateral midline; a single row of dark spots on the soft dorsal fin; caudal fin lined dorsally and ventrally with stripes of yellowish-olive pigmentation extending the length of the fin; and two prominent dark brown to black spots at the caudal-fin base. ROV-based collecting systems are a promising and relatively affordable technology for studying ichthyological diversity on deeper reef habitats, particularly those beyond the reach of technical SCUBA. The discovery and description of P. rota adds to the growing number of Parapercis species that are known to occur in mesophotic and deeper waters.Item Diagnoses for Leiognathus Lacepède 1802, Equula Cuvier 1815, Equulites Fowler 1904, Eubleekeria Fowler 1904, and a new ponyfish genus (Teleostei, Leiognathidae) ; American Museum novitates, no. 3623(New York, NY : American Museum of Natural History, 2008) Chakrabarty, Prosanta.; Sparks, John S.Recent phylogenetic work on ponyfishes has delimited and revealed the interrelationships of major leiognathid clades. To begin to recognize a monophyletic taxonomy for Leiognathidae we diagnose, delimit, and describe a number of ponyfish genera to reflect our current knowledge of their phylogenetic history. Equula Cuvier, 1815, is resurrected from synonymy with Leiognathus Lacepède, 1802, and comprises E. fasciata and E. longispinis. Members of Equula, the sister group to all other members of Leiognathidae, are large-bodied ponyfishes characterized by conspicuous round yellow blotches on the flank. The genus Leiognathus Lacepède, 1802, the sister group to the remaining members of Leiognathidae less Equula, is herein restricted to a clade comprising Leiognathus equulus, L. robustus, and L. striatus. The subgenus Equulites Fowler, 1904, comprising E. leuciscus, E. klunzingeri, and E. laterofenestra, is removed from synonymy with Leiognathus and is elevated to generic rank. The subgenus Eubleekeria Fowler, 1904 is removed from synonymy with Leiognathus and is likewise elevated to generic rank. Eubleekeria encompasses the "Leiognathus" splendens species complex, which is recovered as the sister group to Photopectoralis. To remedy the paraphyly of the remaining species placed within Leiognathus we describe a new genus, Karalla, which is recovered as the sister group to Nuchequula.Item First observation of fluorescence in marine turtles. (American Museum novitates, no. 3845)(American Museum of Natural History., 2015-12-07) Gruber, David F.; Sparks, John S.In recent years, biofluorescence has been observed in an increasing diversity of animals. Biofluorescence has been primarily examined in cnidarians, and it is also known to occur in other marine animal phyla, including Ctenophora, Annelida, Arthropoda, and Chordata. Most recently, the phenomenon has been shown to be phylogenetically widespread and phenotypically variable in cartilaginous and ray-finned fishes. Here we report on the first observation of fluorescence in a marine tetrapod, sea turtles.Item First report of biofluorescence in Arctic snailfishes and rare occurrence of multiple fluorescent colors in a single species. (American Museum novitates, no. 3967)(New York, NY : American Museum of Natural History, 2021-03-18) Gruber, David F.; Sparks, John S.Biofluorescence has recently been reported to be phylogenetically widespread and phenotypically variable across bony fishes, and is most common in tropical coral reef lineages. Here we provide the first documentation of prominent biofluorescence in Arctic fishes including two juvenile specimens of Liparis gibbus (variegated snailfish) collected from the coastal waters of Eastern Greenland, as well as an adult L. tunicatus (kelp snailfish) collected in the Bering Strait off of Little Diomede Island, AK. Observations of L. gibbus were made during nighttime dives within kelp forests in iceberg habitats in Southeastern Greenland in August 2019. The juvenile L. gibbus specimens exhibit both green (523-530 nm) and red (674-678 nm) biofluorescence on discrete anatomical areas, which provides a rare example of multiple fluorescent colors emitted from a single individual. Notably, the adult L. tunicatus emitted only red fluorescence in a bilaterally symmetrical pattern of discrete red dots and blotches. Potential weak green biofluorescence was also noted in a flatfish (Hippoglossoides platessoides) collected in Greenland, but in no other Arctic species. As the distribution and function of biofluorescence in marine fishes is further examined, this report adds context to its widespread geographical and environmental distributions, and shows that, although rare, biofluorescence does occur in Arctic fish lineages.Item In situ observations of the meso-bathypelagic scyphozoan, Deepstaria enigmatica (Semaeostomeae, Ulmaridae). (American Museum novitates, no. 3900)(American Museum of Natural History., 2018-05-09) Gruber, David F.; Phillips, Brennan.; Marsh, Leigh.; Sparks, John S.Deepstaria enigmatica (Semaeostomeae: Ulmaridae) is one of the largest and most mysterious invertebrate predators of the deep sea. Humans have encountered this jellyfish on only a few occasions and many questions related to its biology, distribution, diet, environmental tolerances, and behavior remain unanswered. In the 45 years since its formal description, there have been few recorded observations of D. enigmatica, due to the challenging nature of encountering these delicate soft-bodied organisms. Members of Deepstaria, which comprises two described species, D. enigmatica and D. reticulum, reside in the meso-bathypelagic region of the world's oceans, at depths ranging from ~600 to 1750 m. Here we report observations of a large D. enigmatica (68.3 cm length x 55.7 cm diameter) using a custom color high-definition low-light imaging system mounted on a scientific remotely operated vehicle (ROV). Observations were made of a specimen capturing or "bagging" prey, and we report on the kinetics of the closing motion of its membranelike umbrella. In the same area, we also noted a Deepstaria "jelly-fall" carcass with a high density of crustaceans feeding on its tissue and surrounding the carcass. These observations provide direct evidence of singular Deepstaria carcasses acting as jelly falls, which only recently have been reported to be a significant food source in the deep sea.Item A new species of ponyfish (Teleostei, Leiognathidae, Photoplagios) from Madagascar, with a phylogeny for Photoplagios and comments on the status of Equula lineolata Valenciennes ; American Museum novitates, no. 3526(New York, NY : American Museum of Natural History, 2006) Sparks, John S.A new species of ponyfish in the genus Photoplagios is described from material collected in coastal waters of northeastern Madagascar. Photoplagios antongil, new species, is distinguished from congeners by the presence of a broad midlateral stripe and two darkly pigmented flank patches located ventral to the lateral midline, which are presumably translucent in life but darkly pigmented in preservative due to a concentration of melanophores. The new species is further distinguished from P. leuciscus, the only externally similar species occurring in the region, by the absence of a large translucent triangular patch on the flanks, a much shorter second dorsal-fin spine, a straight predorsal profile, pigmentation pattern on the upper flanks, absence of black pigment in the pectoral-fin axil, and exposed conical oral dentition in two distinct rows. A phylogeny for Photoplagios is provided based on the simultaneous analysis of anatomical features of the light-organ system and nucleotide characters. The taxonomic status of Equula lineolata Valenciennes, in Cuvier and Valenciennes, 1835 is discussed, and the species is herein concluded to be a nomen dubium of uncertain placement beyond the family level.Item Phylogeny and taxonomic revision of Nuchequula Whitley 1932 (Teleostei, Leiognathidae), with the description of a new species ; American Museum novitates, no. 3588(New York, NY : American Museum of Natural History, 2007) Chakrabarty, Prosanta.; Sparks, John S.Nuchequula Whitley 1932, previously considered a subgenus of Leiognathus Lacep‡ede 1802, is elevated to generic rank. Nuchequula is diagnosed by the presence of a distinct saddle-shaped nuchal marking and by the presence of a pigment-free, mitten-shaped region posteroventral to the pectoral-fin base. The genus comprises five species, N. blochii, N. pan, N. nuchalis, N. decora, and a new species described herein. Nuchequula mannusella, new species, is distinguished from its congeners by a unique pigmentation pattern on the dorsal fin and morphology of the lower jaw. Redescriptions are provided for the other species. A phylogenetic analysis based on morphological characters, including features of the light-organ system, indicates that Nuchequula is monophyletic.Item Phylogeny and taxonomic revision of the endemic Malagasy genus Ptychochromis (Teleostei, Cichlidae), with the description of five new species and a diagnosis for Katria, new genus ; American Museum novitates, no. 3535(New York, NY : American Museum of Natural History, 2006) Stiassny, Melanie L. J.; Sparks, John S.The Malagasy cichlid genus Ptychochromis is revised and five new species are described, one of which is presumed to be extinct. The three valid nominal species, P. oligacanthus, P. grandidieri, and P. inornatus, are redescribed with diagnoses provided for each. A phylogeny of ptychochromin cichlids, derived from the simultaneous analysis of morphological features and nucleotide characters from a combination of mitochondrial and nuclear genes is presented. Ptychochromis is diagnosed by a suite of derived features of the pharynx, infraorbital series, and palatine morphology. In addition, the sister taxon to Ptychochromis, Ptychochromoides katria, is removed from Ptychochromoides and placed in its own genus, Katria, which is described herein as new. Katria is diagnosed by a unique pigmentation pattern, the absence of paired anterior gas bladder chambers that approach the neurocranium, an elevated vertebral count, and a slender caudal peduncle. An unnamed clade comprising Ptychochromis and Katria is diagnosed by a suite of derived features of the pharynx, sensory canal system, supraneural patterning, and palatine morphology.Item Phylogeny of the cichlid subfamily Etroplinae and taxonomic revision of the Malagasy cichlid genus Paretroplus (Teleostei, Cichlidae) ; Bulletin of the American Museum of Natural History, no. 314(New York, NY : American Museum of Natural History, 2008) Sparks, John S.A species-level phylogeny for Etroplinae is presented, based on the simultaneous analysis of morphological and nucleotide characters, and species of the endemic Malagasy genus Paretroplus are taxonomically revised, including the description of two new species. Relative to most other cichlid genera, Paretroplus is diagnosed by numerous anatomical features, including morphology of the gas bladder, neurocranium, oral jaws and dentition, and suspensorium. Keys to the genera of Malagasy-South Asian cichlids and to the species of Paretroplus are provided. Paretroplus is endemic to Madagascar and is the sister genus to Etroplus, endemic to southern India and Sri Lanka. Together these two genera comprise the subfamily Etroplinae. Paretroplus comprises 12 species, two of which are described herein as new. Three morphologically distinct clades are recovered within Paretroplus, one comprising the comparatively elongate, primarily riverine and rheophilic species P. damii, P. nourissati, P. tsimoly, and P. lamenabe, new species, the second comprising the deep-bodied, primarily lacustrine species P. polyactis, P. petiti, P. kieneri, P. maculatus, P. menarambo, P. maromandia, and P. dambabe, and the third comprising the shallow-bodied and highly mottled species P. kieneri and P. gymnopreopercularis, new species, which occur in both lentic and lotic habitats. Monophyly of Etroplinae and Etroplus are also discussed and diagnostic anatomical features are presented for both clades. The sister-group relationship between Etroplus and Paretroplus represents a well-corroborated transoceanic link within Cichlidae, a pattern congruent with the Mesozoic fragmentation of Gondwana. The anterior of the gas bladder is highly modified in Etroplinae, reaching its most derived configuration in Paretroplus, in which multiple, structurally complex and rigid anterior bullae expand into large exoccipital recesses, forming a mechanical (5 otophysic) connection between the gas bladder and inner ear. Evolution of the gas bladder, and its function in conferring increased hearing ability, is discussed in terms of the phylogenetic information this structure provides for reconstructing hypotheses of relationships within Cichlidae.Item Review of the Malagasy sicydiine gobies (Teleostei, Gobiidae), with description of a new species and comments on the taxonomic status of Gobius lagocephalus Pallas, 1770. American Museum novitates ; no. 3440(New York, NY : American Museum of Natural History, 2004) Sparks, John S.; Nelson, Douglas W. (Douglas Walter)Malagasy sicydiine gobies are reviewed, compared with other members of the subfamily in the Mascarene region, and a new species belonging to the genus Sicyopterus Gill, 1860 is described on the basis of material collected in northeastern Madagascar. The new species differs from Sicyopterus franouxi (Pellegrin, 1935), the only other known species of sicydiine goby inhabiting the freshwaters of Madagascar, in the number of branched rays in the second dorsal fin, the color pattern of the body and fins, the number and shape of the premaxillary teeth, and the size and number of scales on the nape and abdomen. Sicyopterus franouxi, a taxon described on the basis of a single juvenile specimen, is redescribed based on adult material. The taxonomic status of Gobius lagocephalus Pallas, 1770, a nominal sicydiine species incorrectly ascribed to the Mascarene islands of the western Indian Ocean, is discussed. This species is herein concluded to be a nomen dubium of uncertain placement beyond the subfamilial level.Item Revision of the endemic Malagasy cavefish genus Typhleotris (Teleostei, Gobiiformes, Milyeringidae), with discussion of its phylogenetic placement and description of a new species. (American Museum novitates, no. 3764)(American Museum of Natural History., 2012-12-11) Sparks, John S.; Chakrabarty, Prosanta.Troglobitic cavefishes of the genus Typhleotris, endemic to coastal southwestern Madagascar, are taxonomically reviewed and a new darkly pigmented species, Typhleotris mararybe, is described from an isolated karst sinkhole on the coastal plain below the Mahafaly Plateau. The new species, known only from Grotte de Vitane (Vitany) near the town of Itampolo, is unique among blind cavefishes in being uniformly darkly pigmented, rather than fully depigmented or exceptionally light in coloration. In addition to its dark coloration (vs. depigmented, translucent white body in congeners), the new species can be distinguished from its two congeners, Typhleotris madagascariensis and T. pauliani, by the sculpted, bony (vs. fleshy) appearance of its head with strongly protruding lateral ethmoid, sphenotic, and pterotic bones, and an elevated vertebral count.Item Supplemental Material for 'First report of biofluorescence in Arctic snailfishes and rare occurrence of multiple fluorescent colors in a single species. (American Museum novitates, no. 3967)'(American Museum of Natural History., 2021-03-18) Gruber, David F.; Sparks, John S.Supplemental Material for 'First report of biofluorescence in Arctic snailfishes and rare occurrence of multiple fluorescent colors in a single species. (American Museum novitates, no. 3967)'Item Supplemental Material for 'In situ observations of the meso-bathypelagic scyphozoan, Deepstaria enigmatica (Semaeostomeae, Ulmaridae). (American Museum novitates, no. 3900)'(2018-05-09) Gruber, David F.; Phillips, Brennan; Marsh, Leigh; Sparks, John S.Supplemental Material for 'In situ observations of the meso-bathypelagic scyphozoan, Deepstaria enigmatica (Semaeostomeae, Ulmaridae). (American Museum novitates, no. 3900)'