New records of benthic diatoms (Bacillariophyceae) for Mexico in the Nayarit littoral found in gut contents of  Crassostrea corteziensis  (Mollusca: Bivalvia)

The rhabdocoele turbellarian Paravortex scrobiculariae (Graff) was first described, but not named, by Villot (1878) who discovered this parasite living in the gut of Abra tennis (Montagu) in Brittany. In naming the species, Graff (1882) did not add to Villot's description. Wahl (1906) erected the genus Paravortex to include this form which he had found in Scrobicularia plana (da Costa) and Venerupis decussata (L.) at Trieste and Naples. The first record of P. scrobiculariae in British waters was supplied by Freeman (1957) who, working at Whitstable, Kent, found 8 specimens in 3 out of a sample of 40 S. plana he examined. No further British record appears to have been made.A recent survey has shown Paravortex to be common and widespread in S. plana inhabiting the estuaries of south-west England. As noted by previous workers, Paravortex can be readily seen through the semi-transparent gut wall of its host on account of its pinkish colour; observation is facilitated if the bivalve is maintained in clean sea water for 3–4 days to allow evacuation of some of the gut contents and is most easily performed during the winter months when gametes are not present in quantity. In this study, counts of the Paravortex were made by removing the gut from the surrounding foot tissues and releasing the Paravortex by cutting the gut longitudinally. From each locality, 20–30 S. plana, all within the length range of 30–50 mm, were examined. Paravortex is viviparous, the newly-hatched young being 120–150 μm long; at this stage they are transparent and are easily overlooked amongst the gut contents; thus counts relate chiefly to adults 0·5–1·5 mm in length.

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Colonization of fiber-glass plates by benthic diatoms from subtidal sediment off the coast of Yucatan, Mexico

CICIMAR Oceánides ◽

10.37543/oceanides.v34i1.239 ◽

2019 ◽

Vol 34 (1) ◽

pp. 29

Author(s):

Yuriko Jocselin Martínez Hernández ◽

David Alfaro Siqueiros Beltrones ◽

Pedro Luis Ardisson Herrera

Keyword(s):

Species Composition ◽

Bottom Sediment ◽

Environmental Problem ◽

New Records ◽

Common Species ◽

Benthic Diatoms ◽

Fiber Glass ◽

Colonization Process ◽

Glass Plates ◽

Colonization Period

Benthic diatoms thrive in many types of substrata, either natural or alternative such as the surfaces of large and small boats in which colonization by micro- and macro-organisms (fouling) represents an important economic and environmental problem. Addressing this issue is difficult given the scarce information on benthic diatoms one of the main micro-fouling settlers. Thus, this study aimss to describe the colonization process by diatoms on fiber-glass plates and construct a floristic list of the diatom taxa growing both on these surfaces and their likely source the subtidal bottom sediment. The study was conducted at a coastal site off Telchac, Yucatan (Mexico), where fiber-glass plates were laid over the bottom sediment at a depth of 10 m during four months. Sampling was carried out over successive spaced points in time (1st, 3rd, 4th, 8th, 12th and 16th weeks) after the initial immersion of the plates. At the end 88 taxa growing on the plates and sediment were identified, the most abundant ones being Cocconeis scutellum var. parva, Cymatosira lorenziana, Paralia sulcata, Delphineis surirella var. australis, Actinoptychus senarius, Grammatophora marina and Shionodiscus oestrupii. Included were two new records for the Mexican littorals: Cocconeis latestriata and Navicula uniseriata. Overall species composition differs from previous studies in the area, to which forty-seven taxa are added here, increasing their total number to 210. Our results show the changes in the species composition of the taxocenosis over time, during the initial colonization period, i.e., the period during which there is no intense competition for space. The high percentage of common species between the plates and sediment (similarity) support the hypothesis that subtidal sediment is the most likely source for diatoms colonizing the plates.

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LXXVI.—A list of the Siphonaptera recorded from Ceylon, together with a number of new records

Annals and Magazine of Natural History ◽

10.1080/00222933608655101 ◽

1936 ◽

Vol 17 (97) ◽

pp. 593-599

Author(s):

Gordon B. Thompson

Keyword(s):

New Records

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IPOMOEA LITTORALIS AND IPOMOEA CAPITELLATA VAR. MULTILOBATA : NEW RECORDS FOR UPPER GANGETIC PLAINS OF INDIA

FLORA AND FAUNA ◽

10.33451/florafauna.v24i1pp03-08 ◽

2018 ◽

Vol 24 (1) ◽

Author(s):

JASWINDER KAUR ◽

SATYA NARAIN

Keyword(s):

New Records ◽

Critical Examination ◽

Type Specimens ◽

Gangetic Plains

The floristic exploration and critical examination of specimens collected of family Convolvulaceae from Upper Gangetic Plains of India, resulted in addition of 2 new records for the flora viz. Ipomoea littoralis and Ipomoea capitellata var. multilobata. Detailed description, phenology, ecology, distribution, locality, field number, type specimens examined, illustrations and other relevant notes are provided.

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