Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, Nigeria
Chrysichthys nigrodigitatus and C. auratus are important, highly valued and threatened freshwater species. To contribute with their ecological knowledge, the condition factor and diet of these two congeneric species were studied between April 2005 and April 2006. Food items of fish were evaluated by...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Vicerractoría Investigación
2011-09-01
|
| Series: | Revista de Biología Tropical |
| Subjects: | |
| Online Access: | http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442011000300024&lng=en&tlng=en |
| _version_ | 1797764746925047808 |
|---|---|
| author | Oluwatosin Ebenezer Atobatele Alex Obih Ugwumba |
| author_facet | Oluwatosin Ebenezer Atobatele Alex Obih Ugwumba |
| author_sort | Oluwatosin Ebenezer Atobatele |
| collection | DOAJ |
| description | Chrysichthys nigrodigitatus and C. auratus are important, highly valued and threatened freshwater species. To contribute with their ecological knowledge, the condition factor and diet of these two congeneric species were studied between April 2005 and April 2006. Food items of fish were evaluated by occurrence and numerical abundance methods, and the possible changes among sexes, seasons and sizes were considered. Results showed that generally C. nigrodigitatus were better conditioned than C. auratus. The males of C. nigrodigitatus and females of C. auratus were in better condition than their respective opposite sex throughout the year, and during the wet season compared to the dry. The food items of C. nigrodigitatus and C. auratus were similar and comprised twelve species belonging to five groups: Insecta (three species), Crustacea (five species), Arachnida (one species), Rotifera (one species) and Mollusca (two species). Other food items included fish scales, unidentified green eggs, plant parts, detritus and sand. Insecta and Crustacea dominated the food items in both species. For C. nigrodigitatus, insect consumption increased with fish size, while Crustacea items decreased (from 89.59% for 8.1cm - 12.0cm size class to 1.58% for 20.1cm - 26.0cm size class). However, while C. auratus smaller sized fish preferred Crustacea (98.72% for 8.1cm -12.0cm size class), larger sized fish had both groups in relatively similar amounts. Schoener Overlap Index for both species and between seasons is 1.00. Diet breadth ranged from 0.00-1.47 for C. nigrodigitatus and 0.00-1.32 for C. auratus. Food Richness ranged from 0.00-1.44 for both species. Gut Repletion Index for C. nigrodigitatus and C. auratus are 76.39% and 76.27% respectively. Although, there is considerable similarity and overlap in the utilization of food resource for both coexisting species, condition factor and feeding behavior suggest strategies to reduce intra- and inter-specific competition. Rev. Biol. Trop. 59 (3): 1233-1244. Epub 2011 September 01. |
| first_indexed | 2024-03-12T20:00:10Z |
| format | Article |
| id | doaj.art-c213dc60ab814b109ccc21b26eacd104 |
| institution | Directory Open Access Journal |
| issn | 0034-7744 |
| language | English |
| last_indexed | 2024-03-12T20:00:10Z |
| publishDate | 2011-09-01 |
| publisher | Vicerractoría Investigación |
| record_format | Article |
| series | Revista de Biología Tropical |
| spelling | doaj.art-c213dc60ab814b109ccc21b26eacd1042023-08-02T02:29:44ZengVicerractoría InvestigaciónRevista de Biología Tropical0034-77442011-09-0159312331244S0034-77442011000300024Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, NigeriaOluwatosin Ebenezer Atobatele0Alex Obih Ugwumba1Bowen UniversityUniversity of IbadanChrysichthys nigrodigitatus and C. auratus are important, highly valued and threatened freshwater species. To contribute with their ecological knowledge, the condition factor and diet of these two congeneric species were studied between April 2005 and April 2006. Food items of fish were evaluated by occurrence and numerical abundance methods, and the possible changes among sexes, seasons and sizes were considered. Results showed that generally C. nigrodigitatus were better conditioned than C. auratus. The males of C. nigrodigitatus and females of C. auratus were in better condition than their respective opposite sex throughout the year, and during the wet season compared to the dry. The food items of C. nigrodigitatus and C. auratus were similar and comprised twelve species belonging to five groups: Insecta (three species), Crustacea (five species), Arachnida (one species), Rotifera (one species) and Mollusca (two species). Other food items included fish scales, unidentified green eggs, plant parts, detritus and sand. Insecta and Crustacea dominated the food items in both species. For C. nigrodigitatus, insect consumption increased with fish size, while Crustacea items decreased (from 89.59% for 8.1cm - 12.0cm size class to 1.58% for 20.1cm - 26.0cm size class). However, while C. auratus smaller sized fish preferred Crustacea (98.72% for 8.1cm -12.0cm size class), larger sized fish had both groups in relatively similar amounts. Schoener Overlap Index for both species and between seasons is 1.00. Diet breadth ranged from 0.00-1.47 for C. nigrodigitatus and 0.00-1.32 for C. auratus. Food Richness ranged from 0.00-1.44 for both species. Gut Repletion Index for C. nigrodigitatus and C. auratus are 76.39% and 76.27% respectively. Although, there is considerable similarity and overlap in the utilization of food resource for both coexisting species, condition factor and feeding behavior suggest strategies to reduce intra- and inter-specific competition. Rev. Biol. Trop. 59 (3): 1233-1244. Epub 2011 September 01.http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442011000300024&lng=en&tlng=enChrysichthysfactor de condiciónconducta alimentariacompeticiónReserva Aiba |
| spellingShingle | Oluwatosin Ebenezer Atobatele Alex Obih Ugwumba Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, Nigeria Revista de Biología Tropical Chrysichthys factor de condición conducta alimentaria competición Reserva Aiba |
| title | Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, Nigeria |
| title_full | Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, Nigeria |
| title_fullStr | Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, Nigeria |
| title_full_unstemmed | Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, Nigeria |
| title_short | Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, Nigeria |
| title_sort | condition factor and diet of chrysichthys nigrodigitatus and chrysichthys auratus siluriformes bagridae from aiba reservoir iwo nigeria |
| topic | Chrysichthys factor de condición conducta alimentaria competición Reserva Aiba |
| url | http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442011000300024&lng=en&tlng=en |
| work_keys_str_mv | AT oluwatosinebenezeratobatele conditionfactoranddietofchrysichthysnigrodigitatusandchrysichthysauratussiluriformesbagridaefromaibareservoiriwonigeria AT alexobihugwumba conditionfactoranddietofchrysichthysnigrodigitatusandchrysichthysauratussiluriformesbagridaefromaibareservoiriwonigeria |