Environment and Ecology Research 7(6): 303-312, 2019 http://www.hrpub.org DOI: 10.13189/eer.2019.070601 Succession Patterns and Diversity of Arthropods Associated with Decomposing Domestic Rabbit (Oryctolagus cuniculus L, 1758) in Different Habitats * Izuma Joshua, Noutcha, M. Aline E Department of Animal and Environmental Biology, University of Port Harcourt, Port Harcourt, Nigeria Received Ocotber 14,2019; Revised November 14, 2019; Accepted December 4, 2019 Copyright©2019 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract Succession patterns of arthropods associated 1. Introduction with decomposing domestic rabbit (Oryctolagus cuniculus Linnaeus, 1758) were investigated in exposed and Medico-legal forensic entomology is the involvement of sheltered habitats, located at 4o 53’41.680 "N, 6o 54’39.127 certain necrophagous insects for unraveling activities "E and 4o 54’19.83"N, 6o55’17.36"E respectively, (felonies, murder, suicide and rape) which are criminal University of Port Harcourt, Nigeria. The decomposition of components of the legal system (Okiwelu et al.,2008). It the six domestic rabbits was observed during the onset of also seeks to interpret the events preceding various kinds of the wet season (1st March – 30th April 2017) to identify body injuries and mortalities involving arthropods forensically important insects attracted to them and pre-mortem and post-mortem intervals. Other than determine temperatures and relative humidity influencing ecological interest, carrion decomposition and insect carrion decomposition. Five stages of decomposition: succession occurrence on carrion have been utilized and Fresh, bloated, active decay, advanced decay and dry proven to be of utmost importance in forensic entomology remains stages were observed. The sequence of insect (Mullen and Durden, 2009). The decomposition of carrion succession followed a distinct pattern: dipteran flies first seeks to provide substantial information on nutrient cycling colonized the rabbit carcasses and were succeeded by which is primarily carried out through the activities of coleopterans. A total of 33 species of arthropods, in 23 bacteria, fungi and insects (Mondor et al., 2012). However, families and 7 orders were collected. The insect families soon after death there is a predictable manner in which recorded were: Calliphoridae, Muscidae, Sarcophagidae, insects become the primary colonizers of carrions or Histeridae, Piophilidae, Drosophilidae, Bostrichidae, corpses that provide a biological clock to precisely Stratiomyidae, Staphylinidae, Tabanidae, Carabidae, determine the time elapsed since death (Resh and Carde, Tenebrionidae, Scarabaedae, Cleridae, Formidae, 2009). Sphecidae, Curculionidae and Dermestidae. Three Usua (2007) emphasized that forensic entomology in unidentified insect taxa in Lepidoptera, Orthoptera and Nigeria is at its infancy, stimulating a call for participation Odonata were collected in the exposed habitat, while two and interest in the field of forensic entomology. unidentified species in the class Arachnida; a Macrocheles Preliminary studies of arthropods associated with mite and a non-acarine were collected in both habitats. mammalian carcasses in Rivers state were conducted by Based on frequency of occurrence and role of Calliphorids, Okiwelu et al. (2008) to create awareness on the Chrysomya chloropyga and C.albiceps were the most application of forensic entomology in wildlife conservation forensically significant insects. Temperature apparently to target poachers involved in indiscriminate slaughter of accelerated the rate of decomposition although but there endangered species. Ndueze et al. (2015) reported on the was no significant difference (p>5%) between the rates of period of colonization and succession patterns of decomposition of the carcasses in the two habitats. arthropods associated with four wildlife carcasses in sheltered and exposed habitats. He provided baseline data Keywords Succession Patterns, Rabbit Carcass, for postmortem interval estimates of wildlife species. Decomposition, Exposed, Sheltered Ekrakene and Odo (2015), investigated insects associated with exposed rabbit carrions in Warri, Nigeria and found that insect species varied from geographical location to 304 Succession Patterns and Diversity of Arthropods Associated with Decomposing Domestic Rabbit (Oryctolagus cuniculus L, 1758) in Different Habitats another. Therefore, research is relevant across 1.0-1.8kg, were obtained from the rabbitry of the Faculty of eco-vegetational zones. The domestic rabbit (Orytolagus Agriculture, Rivers State University, Port Harcourt, cuniculus) had been identified as a reliable model in Nigeria. The rabbits were identified, based on the keys of decomposition studies (Ekrakene and Odo, 2015). Ekanem Nagorsen (2002). Each rabbit was euthanized with and Dike (2010) stated that forensic entomology is not well chloroform for 15 minutes to prevent external bleeding and practiced in Nigeria due to the paucity of information. maintenance of body integrity (Tantawi et al., 1996). The Ewuim and Abajue, (2016) reported that forensic science rabbits were placed singly in rectangular cages, 45 × 45 × in Nigeria has not gained full recognition and acceptance in 60cm and mesh size of 2 x 2cm. The three cages containing the judicial system, especially with respect to cases relating rabbit carrions were placed 10 metres apart at each of the to unnatural deaths. There has been trending reports of site. Daily observations were made using the stages of suspicious deaths of domestic animals and humans around decomposition criteria: fresh, bloated, active decay, residential areas (Kyerematen et al., 2013). Therefore, advanced decay and dry remains (Anderson and Studies were conducted to observe the succession patterns VanLaerhoven, 1996; Kyerematen et al., 2013). and diversity of arthropods on carcasses of the domestic rabbit O. cuniculus in exposed and sheltered habitats at the 2.3. Insect Collections/Procedures for Sampling University of Port Harcourt, Rivers State, Nigeria. The Protocol purpose of this study is to provide baseline information on the different forensic insects associated with decomposing Insects were collected, 8:00-10.00 and 14.00-16:00 rabbit O. cuniculus in exposed and sheltered habitats. The hours daily, using sweep net, forceps, hand-picking and findings from this study will be beneficial and can be camel hair brush. Climatic factors (sunlight, rainfall, extrapolated to aid legal investigation in the estimation of relative humidity, ambient temperature, internal postmortem interval in unnatural deaths cases of animals temperature and maggot mass temperature) that might and human in exposed and sheltered habitats. affect the rate of carrion decomposition were also recorded. Temperature was recorded daily with the aid of a glass thermometer. This was followed by the collection of 2. Materials and Methods arthropod specimens on the carrion and its immediate surroundings. The approximate duration of collection of 3.1. Study Area specimens on each carcass was 20 minutes to ensure minimum disturbance at each site; prior to collection, the Studies on decomposing domestic rabbit (O. cuniculus carrion was photographed. Linnaeus, 1758) were conducted at the University of Port Examination began from the head region to the genital Harcourt, Choba, Port Harcourt, Nigeria in exposed and openings to check for eggs (Byrd and Castner, 2009). Eggs sheltered habitats at 4o 53’41.680 "N, 6o 54’ 39.127" E and o o were extracted with the aid of a camel hair brush; half of 4 53’19.83424 "N , 6 55’ 17.35666 "E, respectively. them were preserved in 70% alcohol before transferring Choba is in Obio/Akpor Local Government Area, Rivers o o into another vial containing Kahle’s solution. The other State, Nigeria (4 45’N and 6 50’ E), approximately 20 km half were placed in a container with beef liver to rear to the from the state capital, Port Harcourt. The exposed adult stage for easy identification. Fly larvae were experimental site was on vegetation dominated by these collected from the carrion’s body in batches of 20- 30 per plant species: Manihot esculenta (cassava), Musa vial using forceps. Larvae collected were reared to adult paradesica (plantain), Musa sapietum(banana), stage with beef in vials covered with net mesh and adults Xanthosomamafaffa (cocoyam), Synedrella nodiflora, identified after emergence. The adults were air-dried and Costus sp, Nephrolepis sp, Talinum triangulare, put in 10 ml 70% alcohol in a 25 ml capacity capped Commelina erecta, Peperomia pallucida, Cyathula specimen bottle. They were taken to Ahmadu Bello prostrata, Albizia sp, Phyllanthus sp, Asystasia gangetica, University Museum for identification. Pupae were also Solenostemon monostaehyus, Gissus sp, Setaria barbata. regularly collected from the decomposing rabbit carrion. The sheltered habitat was a green-roofed house of Adult flies were collected using sweep net, while beetles dimensions; Length, width and Height (12.5) × (7.5) × were handpicked and placed singly in labeled containers. (12.5m). Sheltered habitat was approximately 2km apart All adults were fixed in Kahle’s solution at the site of from the exposed habitat. collection, taken to the Department of Animal and Environmental Biology laboratory, dried and mounted in 2.2. Carrion Placement the insect box and kept in the Insect Museum of the Six domesticated