Morphological differences among females of four species of stickleback (Gasterosteidae) from New Brunswick and their possible ecological significance

1987 ◽  
Vol 65 (2) ◽  
pp. 289-295 ◽  
Author(s):  
J. Charles Delbeek ◽  
D. Dudley Williams

Fifteen morphological characters were measured from females of four species of stickleback (Gasterosteidae) collected from the east coast of Canada. Significant differences were found between the species for 12 of these characters. All four species were found to differ significantly in their gill raker number. Gasterosteus had the greatest number of gill rakers followed by Pungitius and Apeltes. A significant negative correlation between gill raker number and prey size was demonstrated; Gasterosteus fed to a greater extent on smaller, planktonic prey, while Pungitius and Apeltes fed on larger, benthic prey. Gasterosteus were found also to have larger pectoral and caudal fin areas, and shorter but wider caudal peduncles, than Pungitius and Apeltes. The larger fins of Gasterosteus are probably a reflection of their increased swimming ability in response to the pelagic phase of their life histories. The longer, narrower caudal peduncles of Pungitius and Apeltes are probably an adaptation to life in weedy habitats where high manoeuverability is desired. The significance of these characters, as well as mouth height, pelvic fin length, body depth, gut length, head length, and pectoral fin length, are further discussed with respect to observed differences in diet, habitat, and life histories.

2007 ◽  
Vol 87 (6) ◽  
pp. 1727-1732 ◽  
Author(s):  
Fernanda F. Cavalcanti ◽  
Carla Zilberberg ◽  
Michelle Klautau

Chondrilla nucula is a morphologically simple species defined by the presence of spherasters in its skeleton. For a long time C. nucula was considered a cosmopolitan species, however, in 1999, a molecular study demonstrated the existence of a species complex with at least four cryptic species, besides C. nucula. At that time, those four new species were not formally described because the morphological differences observed did not reflect species differences and were attributed to plasticity. Since then, researchers working on Chondrilla species suggested that the skeletal organization, the distribution of spherulous cells and the type of surface should be used to differentiate species. Individuals of Chondrilla aff. nucula from one population in Arraial do Cabo, Rio de Janeiro State, Brazil, were collected monthly and analysed in order to test the validity of those three characters to separate the species of Chondrilla. Moreover, to determine if the differences in spicule dimensions previously found were seasonal, we also quantified the diameter of the spherasters throughout the year. Our results demonstrate that all analysed characters are extremely variable and that spicule size can vary even at the same locality. The present study shows the importance of testing the variability of morphological characters before describing new species. Unfortunately, until valid taxonomic characters are found, the Atlantic Chondrilla species will have to remain undescribed.


1987 ◽  
Vol 65 (7) ◽  
pp. 1823-1826 ◽  
Author(s):  
T. D. Beacham ◽  
R. E. Withler

We compared developmental stability as measured by fluctuating asymmetry within individual adults for gill raker and branchiostegal ray number and pectoral and pelvic fin length for three populations of chum salmon (Oncorhynchus keta) and one of pink salmon (Oncorhynchus gorbuscha). There was no association between individual heterozygosity calculated at 10 electrophoretic loci for chum salmon and 13 loci for pink salmon and magnitude of fluctuating asymmetry for the four morphological characters examined. More heterozygous individuals were not less asymmetrical, and thus our results provide no evidence to suggest that increased heterozygosity results in an increased canalization of morphology during development and growth.


ZooKeys ◽  
2018 ◽  
Vol 786 ◽  
pp. 139-153 ◽  
Author(s):  
Richard L. Pyle ◽  
Brian D. Greene ◽  
Joshua M. Copus ◽  
John E. Randall

The new species Tosanoidesannepatricesp. n. is described from four specimens collected at depths of 115–148 m near Palau and Pohnpei in Micronesia. It differs from the other three species of this genus in life color and in certain morphological characters, such as body depth, snout length, anterior three dorsal-fin spine lengths, caudal-fin length, and other characters. There are also genetic differences from the other four species of Tosanoides (d ≈ 0.04–0.12 in mtDNA cytochrome oxidase I). This species is presently known only from Palau and Pohnpei within Micronesia, but it likely occurs elsewhere throughout the tropical western Pacific.


1974 ◽  
Vol 31 (1) ◽  
pp. 55-62 ◽  
Author(s):  
J. S. Loch

Adult lake whitefish (Coregonus clupeaformis) from Clearwater Lake and second generation adults of offspring from Clearwater whitefish transplanted to Lyons Lake were compared with respect to morphometric and meristic characters and isozymes of L-glycerol-3-phosphate dehydrogenase (GPDH). Feeding habits and abundance of pelagic and benthic foods were compared in the two lakes.Gill raker number, lateral line scale count, and interorbital width remained constant between parental and offspring populations. Gill raker length was the main character found to differ between the populations. This was found to be related to the percentage and type of benthic food eaten. Abrasion of the gill rakers is offered as an explanation for the differences in gill raker length. Differences were found in various other meristic and morphological characters, as well as in electrophoretic phenotype frequencies of isozymes of GPDH.


Parasitology ◽  
1930 ◽  
Vol 22 (3) ◽  
pp. 370-398 ◽  
Author(s):  
Harendra Nath Ray

1. The main facts in Brasil's (1907) account of the intracellular schizogony inSelenidium caulleryifromProtula tubulariahave been confirmed. Early stages in the sporogony of this species are described now for the first time.2. Intracellular schizogony is described for the first time inSelenidium mesniliBrasil fromMyxicola infundibulum, and here also the early stages in sporogony are noted for the first time.3. The life histories of Caullery and Mesnil's two unnamed species ofSelenidium(now calledS. spionis(Köll.) andS. foliatumn.sp.) fromScolelepis fuliginosahave been exhaustively studied. No schizogonic phase has been observed in either. The gametocysts, here described for the first time, are found to develop fully only after escape into the sea. The gametocysts ofS. spionisare ovoid, 108μ x 60μ and contain spores with four sporozoites: those ofS. foliatumare spherical, 70μ in diameter, and their spores contain eight sporozoites.4. New or hitherto little known species ofSelenidiumare recorded fromCirratulus cirratusMüll.,Branchiomma vesiculosumMont.,Sabella pavoninaSav.,Pomatoceros triqueterL. andTerebella lepidoriaKühl, and the morphological characters of the trophozoites are described.5. A discussion follows of the value of the diagnostic characters of the genusSelenidium. It is suggested that this genus requires drastic revision and will probably have to be dismembered. Stress is laid, however, on the occurrence in all the gregarines examined, and at all the observed stages of their development, of characteristic chromatic bodies at the anterior end, structures which have hitherto escaped the notice of most observers.


1987 ◽  
Vol 119 (5) ◽  
pp. 465-480 ◽  
Author(s):  
Thomas W. Phillips ◽  
Stephen A. Teale ◽  
Gerald N. Lanier

AbstractPissodes approximatus Hopkins (1911) is a junior subjective synonym of P. nemorensis Germar (1824). The conspecificity of these entities, traditionally considered distinct based only on distribution and slight morphological differences, is corroborated here with comparative studies of ecology, behavior, and morphology. When pheromone-baited traps were deployed during the spring (May–June) and fall (November–December) in several localities to examine seasonal activity, southern populations (P. nemorensis sensu Hopkins) responded only in the fall and northern populations only in the spring, but a population in Virginia responded during both seasons. Laboratory studies found that individuals from five southern populations became reproductively mature under 16:8, 12:12, and 8:16 (L:D) photoperiods but weevils in a New York population did not mature under the 8:16 photoperiod. A two-species model based on strict seasonal isolation between northern and southern populations is rejected. Morphometrics revealed significant differences in six body dimensions and three morphometric ratios among 13 populations, but there was no geographic pattern of differences to suggest the existence of two species. Sexual dimorphism in rostrum length was most pronounced in southern populations but occurred in all five populations in which it was investigated. Examination of male and female genitalia revealed similar variation in northern and southern populations and conflicted with previously reported diagnostic differences. Our study and the results of earlier work lead us to conclude that the populations previously represented by the names P. nemorensis and P. approximatus comprise one widely distributed species and display intraspecific variation in life history and morphological characters.


Zootaxa ◽  
2018 ◽  
Vol 4486 (4) ◽  
pp. 575 ◽  
Author(s):  
MIGUEL VENCES ◽  
ANDREA HILDENBRAND ◽  
KATHARINA M. WARMUTH ◽  
FRANCO ANDREONE ◽  
FRANK GLAW

The subgenus Brygoomantis in the Madagascar-endemic genus Mantidactylus contains 12 nominal species but is in urgent need of taxonomic revision as many additional, genetically divergent but undescribed candidate species have been identified. We here take a first step towards a better resolution of this group by describing a new species, Mantidactylus schulzi sp. nov., occurring at the Tsaratanana and Manongarivo Massifs, differentiated in genetic, bioacoustic and sometimes morphological characters from its closest relatives. We show that upon detailed study, most species in Brygoomantis can be delimited by concordant differentiation of mitochondrial and nuclear DNA, and by bioacoustic and morphological differences. We flag this group of morphologically similar frogs as a test case where molecular data on historical type specimens by ancient DNA methods might be needed to reach a satisfying clarification of taxonomy and nomenclature. However, the status of the new species M. schulzi is not in doubt as it is morphologically distinct from most historical type specimens, and microendemic to a region in northern Madagascar from where no earlier names exist. 


Crustaceana ◽  
2019 ◽  
Vol 92 (8) ◽  
pp. 957-978
Author(s):  
Xiaodong Jiang ◽  
Xugan Wu ◽  
Haining Wang ◽  
Yuhong Yang ◽  
Yongxu Cheng

Abstract Although morphology is always used to distinguish wild Chinese mitten crab (Eriocheir sinensis) populations, whether morphology could be used to identify the pond-reared offspring of wild E. sinensis populations has remained unclear. This study was undertaken to examine the morphological difference of wild E. sinensis (G0) from the Yangtze River (YR), Huang River (HR) and Liao River (LR) as well as their pond-reared offspring (G1). The results showed that: (1) The amount of significantly different parameters of three G1 populations was evidently less than that of three G0 populations; (2) G0 and G1 individuals of each population were clearly separated by principal component analysis, furthermore, three G0 populations were clearly separated while three G1 populations were not well distinguished from each other; (3) discrimination accuracy of G1 individuals in stepwise discriminant analysis was obviously lower than that of G1 populations; (4) G0 and G1 populations were clustered into two separate clusters in the cluster analysis. In conclusion, morphological differences between wild E. sinensis populations had disappeared after one generation of artificial culture, and morphology thus probably cannot be used to distinguish the pond-reared offspring originated from three wild E. sinensis populations.


2013 ◽  
Vol 26 (6) ◽  
pp. 408 ◽  
Author(s):  
Matt A. M. Renner ◽  
Nicolas Devos ◽  
Elizabeth A. Brown ◽  
Matt J. von Konrat

The current paper presents molecular data from three chloroplast markers (atpB–rbcL spacer, trnG G2 intron, trnL–trnF intron and spacer); morphological data, and geographic data to support the recognition of nine species belonging to Radula subg. Odontoradula in Australasia. R. ocellata, the subgeneric type from the Wet Tropics bioregion, is maintained as distinct from its sister species, R. pulchella, from south-eastern Australian rainforests; both species are Australian endemics. Reinstatement of R. allisonii from synonymy, under R. retroflexa, is supported by molecular data and morphological characters, including the absence of triradiate trigones on leaf-lobe cell walls, the apex of lobules on primary shoots not being turned outwards, the oblong-elliptic female bracts, and the perianths having a pronounced wing. Reinstatement of R. weymouthiana, from synonymy under R. retroflexa, is also supported by molecular data and morphological characters, including the presence of a single low dome-shaped papilla over each leaf-lobe cell, and the large imbricate lobules on primary shoots. R. weymouthiana occurs in Tasmania and New Zealand, whereas R. allisonii is a New Zealand endemic. Australian R. retroflexa exhibits differentiation into epiphytic and rheophytic morphs, interpreted as ecotypes. Australian individuals, comprising both epiphytic and rheophytic morphs, are monophyletic and nested within a clade containing individuals from other regions. R. novae-hollandiae is newly reported for the New Zealand Botanical Region, from Raoul Island in the Kermadecs. R. novae-hollandiae exhibits decoupling of morphological and molecular divergence, with Australian individuals forming two clades reflecting geography (a Wet Tropics bioregion clade and a south-eastern Rainforest clade). These clades exhibit equivalent levels of molecular divergence, as observed in R. pulchella and R. ocellata, but no morphological differences. Similar levels of molecular divergence were observed in trans-Tasman populations of R. tasmanica. The New Zealand endemic, R. plicata, is excluded from the Australian flora, and R. cuspidata replaces R. dentifolia for the New Zealand endemic species formerly known by both names.


Zootaxa ◽  
2019 ◽  
Vol 4604 (2) ◽  
pp. 369 ◽  
Author(s):  
RAFAEL BURGER ◽  
FERNANDO R. CARVALHO ◽  
ANGELA M. ZANATA

A new species of Astyanax from the upper rio Paraguaçu basin, Chapada Diamantina, Bahia, Brazil, is described. Astyanax sincora shares characters currently used to define the Astyanax scabripinnis species complex, as highest body depth approximately at vertical through pectoral-fin midlength and a low number of branched anal-fin rays (13–17). It differs from its congeners by a combination of characters, including eight branched dorsal-fin rays, six branched pelvic-fin rays, presence of bony hooks in pectoral and anal fins of males, dark midlateral line or stripe initiating posteriorly to the vertically elongate humeral blotch, and by the presence of 30–35 scales in the median longitudinal series. The generic positioning of the new species and some polymorphic morphological characters in Astyanax are briefly discussed. The degree of completeness of the lateral line in Hyphessobrycon balbus is discussed. [Species Zoobank registration: urn:lsid:zoobank.org:pub:D708FE7E-3FB5-4729-B438-779717F7ED1A] 


Sign in / Sign up

Export Citation Format

Share Document