Morphology of two native catfishes from the Sierra Madre Occidental, México: I. pricei and Ictalurus sp. (Siluriformes: Ictaluridae)

Introduction: Morphotypes of native catfish of the genus Ictalurus (Siluriformes: Ictaluridae) are known to occur in allopatry in the northern Sierra Madre Occidental of Mexico, with only the Yaqui catfish (Ictalurus pricei) taxonomically described. Recent genetic analysis of these morphotypes has revealed the monophyly of the I. pricei complex, which indicates Ictalurus sp. from the Culiacán River and San Lorenzo River basins as its nearest genetic relative and recognizes as an evolutionarily significant unit the Culiacán River and San Lorenzo River morphotypes. Objective: To compare the meristic and morphometric characteristics of the catfish of the Culiacán River basin with its nearest genetic relative, the Yaqui catfish, in order to determine the presence of distinctive morphological characters that support genetic evidence previously reported for these morphotypes. Methods: Catfish specimens were collected during various field expeditions (1990-2012) to remote sites of the Sierra Madre Occidental and conducted in the Yaqui River and Culiacán River basins with the purpose of morphological comparison. Forty-five morphological characters (40 morphometric and five meristic) were examined in 76 adult specimens – 52 Ictalurus sp. and 24 Ictalurus pricei. Three groups were subject to a discriminant function analysis (DFA), including two Ictalurus sp. groups from the Humaya River and Tamazula River sub-basins, representing the Culiacán River basin, and one I. pricei group representing the Yaqui River basin. The standardized measurements and meristic data of the catfish morphotypes were compared by means of DFA. Results: The DFA revealed 12 characters to be significantly different (P < 0.01) among the groups compared. The morphological characters separating the Ictalurus sp. (Culiacán River basin) from the Yaqui catfish were associated with lower anal, pelvic and pectoral fin ray numbers, shorter head and predorsal lengths, shorter longest lateral barbel and longest dorsal ray lengths and a narrower premaxilar dentary plate; and finally longer distances in Ictalurus sp. for dorsal-fin origin to last anal-fin ray base and dorsal-fin origin to posterior end of the adipose fin base. The standardized coefficients for canonical variables 1 and 2 accounted for 85.6 % and 14.4 % of the total variation, respectively. Conclusions: The distinctive morphological characters of the Ictalurus sp. found in the Culiacán River basin, combined with the known mitochondrial evidence for this morphotype, identify it as an evolutionarily significant unit that requires description as a new species based on taxonomical protocols.

Download Full-text

Geographic Variation of the Curve-Billed Thrasher (Toxostoma Curvirostre) Complex

The Auk ◽

10.1093/auk/120.2.311 ◽

2003 ◽

Vol 120 (2) ◽

pp. 311-322

Author(s):

Octavio R. Rojas-Soto

Keyword(s):

Measurement Error ◽

Small Sample Size ◽

Morphological Characters ◽

Color Pattern ◽

Small Sample ◽

Sierra Madre Occidental ◽

Geographic Patterns ◽

Western Group ◽

Sierra Madre ◽

The Mean

Abstract Geographic patterns of variation in morphological characters in the Curve-billed Thrasher (Toxostoma curvirostre) have been recognized by the description of seven subspecies. Twelve standard measurements, as well as three colorimetric characters and two color pattern characters, were analyzed to test whether subspecies limits predict patterns of variation. Measurement error was addressed by measuring each character three times and calculating the mean. A total of 821 male study skins were used, representing 29 locations. A variety of analysis revealed two major groups, an eastern and western group, divided by the Sierra Madre Occidental. Those two groups had previously been recognized as the curvirostre and palmeri groups, respectively. Those groups were also recovered by analysis of mtDNA. The two groups fulfill the requirements for species. The Tiburón Island (T. c. insularis) sample was distinct for several characters; however, small sample size precludes formal taxonomic recommendation. Within the two major groups, most characters showed incongruent clinal patterns of variation that did not match subspecies limits.

Download Full-text

A new species of Petrocephalus Marcusen 1854 (Osteoglossomorpha: Mormyridae) from the Sanaga River basin, Cameroon

Zootaxa ◽

10.11646/zootaxa.2934.1.2 ◽

2011 ◽

Vol 2934 (1) ◽

pp. 20 ◽

Cited By ~ 6

Author(s):

SÉBASTIEN LAVOUÉ

Keyword(s):

River Basin ◽

Electric Organ Discharge ◽

Central Africa ◽

Electric Organ ◽

Morphological Characters ◽

Museum Specimens ◽

Unique Combination ◽

Dorsal Fin ◽

West And Central Africa ◽

A New Species

Petrocephalus similis n. sp. is described from the Djerem River, upper Sanaga basin, in Cameroon. It can be distinguished from all other Petrocephalus from West and Central Africa by an unique combination of morphological characters including: body without melanin mark, 22–24 branched rays in the dorsal fin and 28 or 29 branched rays in the anal fin, mouth commissure under the posterior half of the eye. Petrocephalus similis mostly resembles Petrocephalus sullivani. Yet, P. similis has proportionally a larger mouth and a wider head, and reaches a longer maximum standard length. The electric organ discharge waveform of this species is not known. Molecular comparisons based on cytochrome b nucleotide sequences are congruent with morphological comparisons in independently supporting the distinctiveness of this species from 17 other species of Petrocephalus. Within the genus Petrocephalus, P. similis belongs to a group that is almost exclusively composed of endemic species of Central Africa, pointing out its likely origin from this region. Additional examinations of museum specimens from the Sanaga River basin demonstrate the occurrence of at least two other species of Petrocephalus: Petrocephalus microphthalmus, and a second species which is conservatively assigned to Petrocephalus cf. christyi, pending additional evidence.

Download Full-text

Mammals of the San Pedro-Mezquital River Basin, Durango-Nayarit, Mexico

Check List ◽

10.15560/10.6.1277 ◽

2014 ◽

Vol 10 (6) ◽

pp. 1277 ◽

Cited By ~ 4

Author(s):

Celia López-González ◽

Abraham Lozano ◽

Diego F. García-Mendoza ◽

Alí Ituriel Villanueva- Hernández

Keyword(s):

River Basin ◽

Management Strategies ◽

Museum Specimens ◽

Effective Management ◽

Sierra Madre Occidental ◽

Terrestrial Mammals ◽

San Pedro ◽

Transition Area ◽

Sierra Madre ◽

Anthropogenic Threats

The San Pedro–Mezquital River Basin is located in the southern Sierra Madre Occidental, at the Nearctic– Neotropical transition. The river traverses the Sierra through a canyon that reaches over 1000 m in depth. Based on examination of museum specimens, literature records, and our own collections, we documented the occurrence of 120 species (24.6% of the Mexican terrestrial mammals), 24 endemic to Mexico. Richness was comparable with other megadiverse areas of Mexico, and higher than any other Nearctic–Neotropical transition area, moreover species richness is likely to rise as survey continues. Contrary to expectation, distribution of mammals across the basin not only reflected the Nearctic–Neotropical divide, but a third fauna that is a mixture of tropical, temperate and desert species was identifiable at the canyon. Anthropogenic threats including damming of the river, uncontrolled cattle grazing, and pollution from domestic sources, call for effective management strategies to preserve one of the most biodiverse areas of Mexico.

Download Full-text

Phenotypic plasticity in Barilius vagra (Hamilton, 1822) (Teleostei: Danionidae) from two geographically distinct river basins of Indian Himalaya

Journal of Threatened Taxa ◽

10.11609/jott.7414.13.13.19976-19984 ◽

2021 ◽

Vol 13 (13) ◽

pp. 19976-19984

Author(s):

Sumit Kumar ◽

Sharali Sharma ◽

Deepak Singh

Keyword(s):

Phenotypic Plasticity ◽

River Basin ◽

Function Analysis ◽

Mesh Size ◽

River Basins ◽

The Body ◽

Morphometric Traits ◽

Morphometric Characters ◽

Indian Himalaya ◽

Significant Difference

Truss-based morphometric analysis was used to examine phenotypic plasticity of Barilius vagra (Hamilton, 1822) inhabiting the tributaries of the Alaknanda (Ganga River basin) and Chenab (Indus River basin), two geographically distinct river basins in the Indian Himalaya. Fourteen landmarks were connected to generate a truss network of 90 parameters on the body of fish. Eighty morphometric traits out of ninety morphometric measurements explained statistically significant difference among six sampling locations of Barilius vagra from streams in the Alaknanda and Chenab basins. Discriminant function analysis revealed 82% of Barilius vagra specimens originally classified into their own groups. 95% of the variance was explained by 13 principal components. Morphometric characters (1–6, 1–13, 2–5, 2–6, 2–14, 3–6, 4–6, 4–14, 6–12, 7–8, 7–9, 10–11, and 13–14) contributed greatly in differentiation of B. vagra populations from different river basins. The Alaknanda basin reflected some mixing within populations, which may be due to common environmental conditions and fish migration in these streams. This study will be helpful in framing site-specific conservation and management strategies, such as net mesh size selection, avoiding overexploitation, stock augmentation and food availability for different fish populations.

Download Full-text

Redescription of the paedomorphic goby Schindleria nigropunctata Fricke & El-Regal 2017 (Teleostei: Gobiidae) from the Red Sea

Zootaxa ◽

10.11646/zootaxa.4615.3.2 ◽

2019 ◽

Vol 4615 (3) ◽

pp. 450-456

Author(s):

HARALD AHNELT

Keyword(s):

Red Sea ◽

Species Delimitation ◽

Morphological Characters ◽

Pectoral Fin ◽

Dorsal Fin ◽

Fin Ray ◽

Fin Rays ◽

Shaped Pattern ◽

Colored Body ◽

Pectoral Fin Rays

Schindler’s fishes (Schindleria) are extremely paedomorphic and only a few morphological characters are suitable for species delimitation of these tiny fishes. Three of these key morphological characters, the (i) origin of the dorsal fin relative to the anal fin, (ii) number of vertebrae and (iii) coloration, need reinterpretation in a recently described species, Schindleria nigropunctata. To avoid nomenclatorial problems S. nigropunctata is redescribed from the type material. This species is characterized by 16–17 dorsal fin rays, 16 pectoral fin rays, origin of the anal fin ventral to the 8th dorsal fin ray, 37–38 myomeres, a uniform greyish-white colored body (preserved) and a trunk without obvious pigmentation (no black pigment spots). The eyes are dark grey with a silvery cornea. Dorsally on the cornea are blackish melanophores arranged in a sickle-shaped pattern.

Download Full-text

Identification of larval and juvenile Canadian Atlantic gadoids with comments on the systematics of gadid subfamilies

Canadian Journal of Zoology ◽

10.1139/z82-432 ◽

1982 ◽

Vol 60 (12) ◽

pp. 3420-3438 ◽

Cited By ~ 17

Author(s):

Douglas F. Markle

Keyword(s):

Morphological Characters ◽

Good Evidence ◽

Morphological Similarity ◽

Caudal Fin ◽

Caudal Skeleton ◽

Dorsal Fin ◽

Fin Ray ◽

Fin Rays ◽

Primitive State ◽

Additional Support

An attempt to identify larvae and juveniles of Gaidropsarus led to a broader survey of gadoid morphology. Representative specimens of all gadoid families and all Canadian Atlantic gadid species were examined for selected morphological characters. The polarity of these character states was examined using a cladistic approach and led to the conclusion that the gadids are composed of three groups, recognized herein as subfamilies: Gadinae, Lotinae, and Phycinae. The most informative structure examined was the caudal skeleton, which showed three characters with an obvious primitive state in some gadids: presence of X and Y bones, 6 "primary" caudal fin rays, and low (<40) total caudal fin ray counts. Dorsal fin structure, which has been the basis of previous gadid systematic arrangements, is also shown to be informative, providing good evidence of relationship within gadines and phycines. The proposed groupings receive some additional support in the gross morphological similarity of their larvae.

Download Full-text

Identification of sibling species in the genus Eucyclops from water-bodies of Ukraine and Russia using crossbreeding studies

Ecology and Noospherology ◽

10.15421/031406 ◽

2014 ◽

Vol 25 (1-2) ◽

pp. 61-68 ◽

Cited By ~ 1

Author(s):

V. I. Monchenko ◽

L. P. Gaponova ◽

V. R. Alekseev

Keyword(s):

Cryptic Species ◽

River Basin ◽

Black Sea ◽

Species Complex ◽

River Basins ◽

Water Bodies ◽

Similar Species ◽

Basin Water ◽

Different Populations ◽

Baltic Sea Basin

Crossbreeding experiments were used to estimate cryptic species in water bodies of Ukraine and Russia because the most useful criterion in species independence is reproductive isolation. The problem of cryptic species in the genus Eucyclops was examined using interpopulation crosses of populations collected from Baltic Sea basin (pond of Strelka river basin) and Black Sea basin (water-reservoires of Dnieper, Dniester and Danube rivers basins). The results of reciprocal crosses in Eucyclops serrulatus-group are shown that E. serrulatus from different populations but from water bodies belonging to the same river basin crossed each others successfully. The interpopulation crosses of E. serrulatus populations collected from different river basins (Dnipro, Danube and Dniester river basins) were sterile. In this group of experiments we assigned evidence of sterility to four categories: 1) incomplete copulation or absence of copulation; 2) nonviable eggs; 3) absence of egg membranes or egg sacs 4) empty egg membranes. These crossbreeding studies suggest the presence of cryptic species in the E. serrulatus inhabiting ecologically different populations in many parts of its range. The same crossbreeding experiments were carries out between Eucyclops serrulatus and morphological similar species – Eucyclops macruroides from Baltic and Black Sea basins. The reciprocal crossings between these two species were sterile. Thus taxonomic heterogeneity among species of genus Eucyclops lower in E. macruroides than in E. serrulatus. The interpopulation crosses of E. macruroides populations collected from distant part of range were fertile. These crossbreeding studies suggest that E. macruroides species complex was evaluated as more stable than E. serrulatus species complex.

Download Full-text