Helminthofauna of Opisthonema liberate and Harengula thrissina (Osteichthyes: Clupeidae) from Chamela Bay, Jalisco, Mexico

We collected helminths from the "sardines" Harengula thrissina (N = 61) and Opisthonema libertate (n = 43), from Chamela Bay, Jalisco State, Mexico (12 and six species, respectively). The nematode Pseudoterranova sp., reached the highest values of prevalence and mean abundance in O. libertate (11.6% and 0.13 worms per host, respectively), while in H. thrissina the digenean Parahemiurus merus reached a prevalence of 49.1% and a mean abundance of 1.40 worms per host. Low similarity values (qualitative and quantitative) between helminths of both host species is a result of their opportunistic feeding habits (100% of the parasitic species in H. thrissina and 66% of those from O. libertate infect their host from prey) and differential exposure to helminth larvae.     

Helminths from the fish Dormitator maculatus (Osteichthyes: Eleotridae) from Alvarado, Veracruz, Mexico

Dormirator maculatus (n=184) was collected in the Alvarado Lagoon, Mexico during a year period (Oct. 1993-1994). In the helminthologic review, the presence of Clinostomum complanatum (82.3%), Neoechinorhynchus golvani (76.1%), Spiroxys sp. (21.3 %), and Camallanus sp. (6.2%) was registered. Reduction of the hematocrit caused by such infection is significant (t, a= 0.05).     

A new species of Hysterothylacium (Nematoda: Anisakidae) parasite of Ariopsis guatemalensis (Osteichthyes: Ariidae) from Tres Palos lagoon, Mexico

Hysterothylacium perezi n. sp. is described from the intestine of the "cuatete" Ariopsis guatemalensis Günther, 1864 (Osteichthyes: Ariidae), in Tres Palos, a coastal lagoon located in the Mexican Pacific basin. The new species differs from all other species of Hysterothylacium Ward and Magath, 1917, in possessing a spinous postcloacal pad. In addition, H. perezi is readily distinguished from the 21 species described in fishes from America and Hawaii by having the greatest number of caudal papillae (47 to 51 pairs + 1 single, precloacal papillae). This species is the third described from hosts inhabiting estuarine environments in America and the fourth reported in Mexico.     

A new Vaccinium (Ericaceae: Vaccinieae) from Guerrero,Mexico

Vaccinium wilburii, a striking epiphyte with pink flowers and woody tuberous roots, is described, illustrated, and compared with similar species.     

A new species of Eimeria (Apicomplexa, Eimeriidae) from the weedy sea dragon Phyllopteryx taeniolatus (Osteichthyes: Syngnathidae)

A new species of intestinal coccidian is described from the weedy or common sea dragon Phyllopteryx taeniolatus housed at the New England Aquarium in Boston and at the Shedd Aquarium in Chicago, USA. Live oocysts of Eimeria phyllopterycis sp. n. are spherical, 30.9 (28.0-34.4) microm, with a thin, single-layered wall. Both a micropyle and oocyst residuum are absent and a large polar granule is sometimes present. Sporocysts are ellipsoidal and elongate, 24.3 x 10.4 (23.4-25.6 x 9.2-11.2) microm, with Stieda and substieda bodies; shape index (length/width) 2.33 (2.14-2.70). A sporocyst residuum is present, consisting of numerous granules of various sizes. Sporozoites each possess 3 refractile bodies. Preliminary evidence suggests that the coccidian may affect the health of sea dragons; however, it could not be determined whether this parasite caused significant morbidity or mortality.     

A new genus and species of philometrid (Nematoda) from the subcutaneous tissue of the crevalle jack, Caranx hippos (Osteichthyes), from the southern Gulf of Mexico

A new genus and species of nematode, Caranginema americanum n. gen., n. sp. (Philometridae), are described from gravid, subgravid, and nongravid female specimens collected from the subcutaneous tissue of the fish (crevalle jack) Caranx hippos (Carangidae, Perciformes) from the coral reef El Cabezo, southern Gulf of Mexico, Mexico. Caranginema, assigned to the Philometrinae, differs from other genera of this subfamily mainly in the presence of 2 conspicuous parallel cordons on either side, extending along nearly the entire body length and demarcating narrow smooth lateral fields and in having the remaining body surface with numerous ornamentations forming irregularly scattered, transversely elongated narrow cuticular molds. The new species is characterized mainly by the presence of 3 large, sclerotized esophageal teeth protruded out of the mouth, the number and arrangement of cephalic papillae (8 papillae in 4 pairs of external circle and 4 single papillae of internal circle), the length and structure of the esophagus, and by the body length of gravid and subgravid females (267 and 258 mm, respectively). Caranginema americanum is the seventh philometrid species reported from marine and brackish water fishes in Mexico.     

Cicesetrema unami n. gen., n. sp. (Digenea: Cryptogonimidae: Cryptogoniminae) from Paralichthys californicus (Ayres, 1859) (Osteichthyes: Pleuronectiformes: Paralichthydae) in San Quintin Bay, Baja California, Mexico

Cicesetrema unami n. gen., n. sp. (Digenea: Cryptogonimidae) is described from the intestine of the California halibut, Paralichthys californicus, from San Quintin Bay, Baja California, Mexico. The new genus is distinguished from other members of the Cryptogoniminae in having vitellaria that form asymmetric bunches of follicles and extend in lateral fields from the level of the ovary posteriad beyond the testes. In addition, the species in the new genus possess a subterminal, funnel-shaped oral sucker that is prominent when protruded but usually retracted in a fold at the anterior end.     

Philactis fayi (Compositae) : A new species from Mexico

The new species is the fourth member of the genus. Morphologically, it is most closely allied toP. liebmannii, but there are ample qualitative and quantitative differences between them. The chromosome numbers ofP. liebmannii andP. nelsonii are 2n = 56 whileP. zinnioides is 2n = 84.Philactis fayi is 2n = 28 and is considered to represent the diploid complement that was probably involved in the production of the other species through hybridization and chromosome doubling.     

Metastevia (Compositae: Eupatorieae): A new genus from Mexico

A new genus and species from Mexico,Metastevia hintonii, is described. The genus, considered to be closely related to and derived fromStevia, differs in seven morphological features from all known species ofStevia. The reasons for recognizing the new genus are discussed in detail.     

A new species of Sicyos (Cucurbitaceae) from Chiapas,Mexico

Sicyos motozintlensis is described from the vicinity of Motozintla de Mendoza, Chiapas. It shows a strong similarity toS. chiriquensis Hammel & D’Arcy from Panama.     

A new species of Malaxis (Orchidaceae) from Guerrero, Mexico

Malaxis molotensis, a new orchid species from a wet cloud forest of the Sierra Madre del Sur, Guerrero, Mexico is described and illustrated. In habit and floral structure it resembles the widespread M. histionantha but differs in the elliptic labellum with incurved distal margin, and elongate, oblong-falciform pollinaria.     

A new species of Mimosa (Leguminosae) from Coahuila,Mexico

Mimosaunipinnata from the Sierra de San Marcos in the Cuatro Ciénegas Basin of central Coahuila, Mexico, is described. It is unique among mimosas in having oncepinnate leaves.     

A new species of Malaxis (Orchidaceae) from Morelos, Mexico

A new species from the Mexican state of Morelos, Malaxis lyonnetii, is described and illustrated. It is similar to M. lepanthiflora but is distinguished by its much smaller flowers, distally uncinate basal lip lobes, and entire, rounded apical lip lobe.

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Resumen  Se describe e ilustra a Malaxis lyonnetii, una nueva especie del estado mexicano de Morelos. Esta especie es similar a M. lepanthiflora, de la que se distingue por las flores mucho menores, los lóbulos basales del labelo distalmente uncinados y el lóbulo apical del labelo entero y redondeado.

     

A new species of ceratozamia (Zamiaceae) from Chiapas,Mexico

Ceratozamia norstogii sp. nov. from Chiapas, Mexico is described. This species is distinct from all others in the genus in that it has a straight rachis with very narrow leaflets (3–10 mm wide) which are strongly curved and almost round in cross section when dried. It is known only from Chiapas, Mexico and in cultivation.     

A new species of Polymnia (Compositae: Heliantheae) from Mexico

Polymnia mcvaughii from Jalisco, Mexico, is described as new. This herbaceous species appears to belong in the mainstream of evolution within the genus. It exhibits marked affinities to several species, but most closely resemblesP. oaxacana Schultz-Bip. Illustrations of important features are included, along with a list of key characteristics.     

A new species of Viguiera (Asteraceae: Heliantheae) from Mexico

AlthoughViguiera hidalgoana, a new species from Hidalgo, Mexico, bears a superficial resemblance toV. dentata, it is clearly related to certain woody species of seriesGrammatoglossae.