Unidentified Food Research Articles

A numerical study of turbulent mixing parameters at the Nile Delta, north of the Egyptian Coast

A study was conducted in Badagry Creek in Lagos, Nigeria on food and feeding habits and reproduction of Frillfin goby (Bathygobius soporator). Data collected from the study intend to serve as a baseline for carrying out further study on the fishes and fisheries of this water body. B. soporator is one of the numerous and diverse fishes of the family Gobiidae which share certain similarities in their life histories. Gobies are among the most successful fishes. They are resident intertidal species which could be found in pools, rocky pools, lagoons, creeks and estuaries. Specimens were collected from the Badagry Creek via Oto-Awori Fish Jetty between January, 2008 and January, 2009. Foods and feeding habits and reproduction were studied in this creek. Seven groups of food items were encountered in the stomachs of the fish, viz; Crustaceans, Pisces, Insects, Detritus, Bivalves, unidentified food materials and Gastropods. The most eaten of these were the crustaceans contributing 34% by number and 38.30% by frequency of occurrence. The presence of other fish species in the stomachs explained the piscivorous habit while the unidentified food materials demonstrate its herbivorous character. Its predatory and carnivorous tendency was exhibited by the presence of insects, bivalves, crustaceans, and gastropods. Presence of sand grains was an indicator of its benthic nature. The specimens were classified as either male or female. Four hundred and seventy and five specimens representing 98.95 and 1.05% of total catch were classified as males and females, respectively giving 1 (male): 0.01 (female) sex ratio. This is significantly different (P>0.05) from the expected or theoretical one male:one female ratio and not in conformity with sex ratios that were reported for some fishes in the adjacent Ologe, Lagos, Lekki and Epe lagoons which favoured more females. The Gonadosomatic index (GSI) of this species varied from 0.00 to 2.89%, meaning less than 2.89% of the fish’s body mass was converted to gonads for reproduction. The pre-spawning and spawning stages of this species contributed 86.75 and 13.25% of the specimens, respectively. Post spawning stages were absent. Key words: Gonadosomatic index, spawning, Ologe, Badagry, Lekki, Epe.

Growth patterns, diet composition and reproduction in the ten pounder, Elops lacerta from Ologe lagoon, Lagos, Nigeria

Ten pounder, Elops lacerta, a member of the family Elopidae is a tropical and subtropical fish species. Growth patterns, food and feeding habits and reproduction of 317 specimens of E. lacerta were investigated in Ologe lagoon, Lagos, Nigeria. Diurnal and nocturnal fishing activities were carried out in the lagoon using cast and gill nets. The specimens examined ranged from 90375mm total length (TL) and weighed 4.7214g body weight (BW) respectively. Of the specimens 49.5% were juveniles, 36.3% fingerlings and 14.2% adults. Specimens were classified as unsex, males and females their growth exponential “b” values were allometric and 2.40, 2.27 and 2.27 respectively meaning the fish become lighter for its length as it grows. These values accounted for the robustness of the fish in Ologe. High correlation coefficient was observed in E. lacerta with r=0.76, 0.97, and 0.88 for unsex, male and female specimens respectively. 158 males and 64 females were caught giving 1male:0.41female sex ratio. This was significantly different (P>0.05) from the expected 1male:1female. Diet of the fish consisted of shrimps, plant materials and unidentified food mass. Presence of fish and shrimps in stomachs of the fish indicated its piscivorous and predatory tendency while plant materials connoted its herbivorous habit.

Bisphenol A diglycidyl ether (BADGE) migrating from packaging material ‘disappears’ in food: reaction with food components

Bisphenol A diglycidyl ether (BADGE) is widely used as a monomer for coatings and adhesives for food-contact applications. Previous publications indicate that, after migration from packaging into foodstuffs, BADGE undergoes various reactions with unidentified food components. In order to elucidate the fate of BADGE, losses were determined after incubation with different foodstuffs and food components. Food proteins were identified as the main reaction partner with BADGE. Adduct formation was found with nucleophilic side-chains of amino acids. In vitro, cysteine exhibited significant activity. The previously reported occurrence of methylthio-derivatives of BADGE in foodstuffs was shown to originate from the reaction of BADGE with methionine. BADGE-methylthio derivatives can, therefore, be used as marker substances in foodstuffs for protein reactions with BADGE. The reported results offer a new viewpoint on the evaluation of BADGE migration. The hydrolysis and hydrochlorination derivatives subject to European legislation make up only a fraction of the totally migrated BADGE, and a further concern is that the toxic or allergenic potential of the protein adducts are unknown.

Stable carbon, nitrogen, and sulfur isotopes in a prairie marsh food web

Carbon, nitrogen, and sulfur stable isotope ratios of primary producers and consumers of the Delta Marsh, Manitoba were determined to assess the importance of different primary producers as sources of organic matter in the food web. Metaphyton and submersed macrophytes had distinct δ13C and δ15N values. Emergent macrophytes and periphyton could not be separated from each other but were clearly different from metaphyton and submersed macrophytes. The most abundant marsh consumers had δ13C values similar to those of emergent macrophytes, periphyton, and floating macrophytes but unlike those of metaphyton or submersed macrophytes, indicating that the last two primary producer groups were not important sources of organic matter to the food web. Several groups of invertebrates had δ13C values lower than emergent macrophytes and periphyton, suggesting that there may be other important unidentified food sources. δ34S values for surface water sulfate, pore water sulfide, and sediment were distinct and allowed metaphyton, emergent macrophytes, and submersed macrophytes to be separated. The δ34S value of chironomids was close to that of emergent macrophytes, suggesting that organic matter flow reaches chironomids through emergent macrophyte detritus. In this freshwater ecosystem, stable sulfur isotope data are potentially useful for distinguishing between periphyton- and emergent macrophyte-derived organic matter that is not possible based solely on δ13C and δ15N data.

Diet and feeding behavior of semi-free ranging mandrills in an enclosed gabonais forest

Twelve wild born mandrills (Mandrillus sphinx), six males, six females, were studied in a 1.4-ha forest enclosure in Gabon Africa. Seventy-six percent of their food was obtained from the ground (45% unidentified food objects foraged from the leaf litter, 21% from ground plants, and 10% animal matter) while 23% was taken from arboreal sources (10% from trees, 10% from vines, and 3% from shrubs). Plant parts eaten include seeds, roots, fruits, stem pith, apical branch ends, mature and immature leaves, nuts, buds, blossoms, and bark. There were significant dietary differences between sexes. There were also individual dietary differences both in preferred foods and arboreal vs terrestrial foraging locations. At nearly all times of the day at least 70% of the study group was on the ground. Sixty-four percent of their time was spent feeding, with females spending more time feeding than males. High rates of feeding were seen throughout the day, with high individual variances, which is explained by individual food preferences and a temporal partitioning of the food resources. These findings are compared to those observed in wild mandrills and other baboons.

Notes on Siptornis striaticollis (Furnariidae) in Peru

The Spectacled Prickletail (Siptornis striaticollis) is a monotypic furnariid previously recorded only from the subtropical zone of the middle and upper Magdalena Valley in Colombia and the east slope of the Ecuadorian Andes (Mapoto) (Chapman, Bull. Am. Mus. Nat. Hist. 36, 1917; Chapman, Bull. Am. Mus. Nat. Hist. 55, 1926). In view of the paucity of information on Siptornis, we offer the following observations and report the first occurrence of the species in Peru. In 1978, during ornithological investigations in the Department of Cajamarca in northern Peru, we found Siptornis striaticollis northeast of Huancabamba, ca. 2 km south of Carmen, on the Sapalache-Namballe mule trail (OSOS’ S, 7922’ W). We saw these birds daily from 2 to 17 July foraging with large mixed-species flocks in patches of cloud forest between 1,660 m and 1,880 m elevation. Occasionally when a mixed-species flock assembled in an isolated cluster of trees, we made exact counts of arriving and departing individuals. Siptornis was a regular, low-density participant, with a maximum of three to four individuals per flock. Common flock members included the furnariids Crunioleuco curtata, Anabacerthia striaticollis, and Xenops rutilans, and the antwren Terenuru callinota. The prickletails foraged by creeping along branches, and probing moss clumps, clusters of dead leaves, fruticose lichens, and bark crevices at the level of the forest subcanopy and edge 5-15 m above ground. Several times individuals were seen hanging “paridlike” from petioles of Cecropia leaves, picking unidentified food items from undersides of leaflets. Among species that occur in the same area, Siptornis most closely resembles Xenops rutilans in behavior, size, coloration, and plumage pattern. Both Siptornis and Xenops tapped sporadically on limbs, often bracing the tail against the bark when probing deep crevices. During light rain or dense fog we often located these birds by their faint tapping sounds. On 9 July, after watching a large mixed-species flock pass over the trail, Eley heard a peculiar high-pitched trill coming from the top of a nearby bush. Immediately afterward, a Siptornis hopped into view and perched upright in the bush about 2 m above the trail. Another motionless individual about0.5 m from the first bird and in the interior of the bush answered the trill with a similar call. We heard no other vocalizations of this species. Siptornis striaticollis appeared most closely to fill the ecological niche of piculets of the genus Picumnus. In most subtropical cloud forest throughout eastern Peru and Bolivia at least one species of piculet occurs (Meyer de Schauensee, A guide to the birds of South America, Livingston Publ. Co., Wynnewood, Penn., 1970, and pers. observ.), but piculets are unknown in subtropical forest in the eastern Andes north of the Mararion River, where Siptornis occurs. Perhaps Siptornis and Picumnus are ecologically incompatible. Our three specimens, all males, are deposited at the Louisiana State University Museum of Zoology (LSUMZ). Data from these specimens are listed in Table 1. We thank Richard D. Semba and Manuel Sanchez S. for field assistance. J. Van Remsen, H. Douglas Pratt, John P. O’ Neill, and John Weske read the manuscript. We are most grateful to John S. McIlhenny and Babette M. Odom for their generous support of the field work of the LSUMZ.