Papa (samaki)
Papa ni kundi la spishi 500 za samaki wenye kiunzi cha gegedu badala ya mifupa. Gegedu ni dutu ya kunyambuliwa kama mpira mgumu lakini laini kuliko mifupa kamili. Karibu spishi zote za papa wanaishi katika maji ya chumvi baharini.
Papa wengi ni wavindaji wanaokula samaki na wanyama wengine wa baharini. Spishi kadhaa wanahofiwa kwa sababu kushika wanadamu. Lakini papa wakubwa sana hula planktoni kama nyangumi wakubwa.
Papa mkubwa kabisa ni papa nyangumi (Rhincodon typus) anayefikia urefu wa mita 14 na uzito wa tani 12 ambaye ni pia samaki mkubwa kabisa duniani na hula planktoni. Spishi ndogo kabisa ni Etmopterus perryi, wenye urefu wa sentimita 21 tu.
Spishi nyingi za papa ziko hatarini ya kupotea kwa sababu wanavuliwa mno.
Papa huwa na meno mengi yanayoendelea kukua muda wote wa maisha yake mstari baada ya mstari wa meno yanayoanza kukua nyuma ya meno ya nje na kuchukua nafasi yao mfululizo.
Wana uwezo mkubwa wa kunusa ndani ya maji hasa damu ya kiumbe aliyeumizwa kwenye umbali wa kilomita. Kupitia ngozi wanatambua pia mwendo ndani ya maji na wanaelekea penye chanzo cha mwendo.
Spishi nne wametambuliwa kuwa ni hatari kwa wanadamu. Lakini jumla ya ajali ambako mwanadamu anang'atwa na papa ni takriban 100 kwa mwaka kote duniani; mara nyingi watu wanajeruhiwa na mwaka 2007 kuna ya kifo kimoja kutokana na papa. Wataalamu wanajadiliana kama papa wanashambulia kweli au kama wanajisikia mara nyingi wameshambuliwa na watu wanaowakaribia mno au kama papa anamchanganya mwanadamu na windo la kawaida.
Kinyume chake kuna papa milioni 200 wanaouawa kila mwaka na wanadamu.
Alopias pelagicus, Karage Mdogo (Pelagic thresher) au Kinengwe Alopias superciliosus, Karage Macho-makubwa (Bigeye thresher) au Kinengwe Alopias vulpinus, Karage wa Kawaida (Common thresher) au Kinengwe Carcharhinus albimarginatus, Papa Mapezi-ncha-nyeupe (Silvertip shark) Carcharhinus amblyrhynchos, Papa-miamba Kijivu (Grey reef shark) Carcharhinus amboinensis, Papa Macho-nguruwe (Pigeye shark) Carcharhinus falciformis, Papa Bunshu (Silky shark) Carcharhinus humani, Papa-miamba wa Human (Human's whaler shark) Carcharhinus leucas, Papa-fahali (Bull shark) Carcharhinus limbatus, Papa Mapezi-ncha-nyeusi (Blacktip shark) Carcharhinus longimanus, Papa Mapezi-ncha-fedha (Oceanic whitetip shark) Carcharhinus macloti, Papa Pua-ngumu (Hardnose shark) Carcharhinus melanopterus, Papa Karaji (Blacktip reef shark) Carcharhinus plumbeus, Papa Kahawia (Sandbar shark) Carcharhinus sealei, Papa Doa-jeusi (Blackspot shark) Carcharhinus sorrah, Papa Mkia-doa (Spot-tail shark) Carcharias taurus, Papa Meno-chakavu (Sand tiger shark) Carcharodon carcharias, Papa Mweupe Mkubwa (Great white shark) Eridacnis radcliffei, Papa-paka Mdogo (Pygmy ribbontail catshark) Eridacnis sinuans, Papa-paka wa Afrika (African ribbontail catshark) Etmopterus sentosus (Thorny lanternshark) Galeocerdo cuvier, Papa Ngusi (Tiger shark) Hemipristis elongata (Snaggletooth shark) Hexanchus griseus, Papa Matamvua-sita Kijivu (Bluntnose sixgill shark) Hexanchus nakamurai, Papa Matamvua-sita Macho-makubwa (Bigeyed sixgill shark) Holohalaelurus grennian (Grinning Izak) Holohalaelurus melanostigma (Crying Izak) Hypogaleus hyugaensis (Blacktip tope) Isurus oxyrinchus, Papa Nyamzani au Nyamarasi (Shortfin mako shark) Loxodon macrorhinus (Sliteye shark) Mustelus manazo (Starspotted smooth-hound) Mustelus mosis (Arabian smooth-hound) Nebrius ferrugineus, Papa Usingizi Hudhurungi au Guigui (Tawny nurse shark) Negaprion acutidens (Sicklefin lemon shark) Prionace glauca, Papa Buluu (Blue shark) Pristiophorus nancyae, Papa-msumeno wa Afrika (African dwarf sawshark) Pseudoginglymostoma brevicaudatum, Papa Usingizi Mkia-mfupi (Short-tail nurse shark) Rhincodon typus, Papa Nyangumi, Zambarani au Vaame (Whale shark) Rhizoprionodon acutus, Papa Marbui (Milk shark) Scoliodon laticaudus, Papa Sumbwi (Spadenose shark) Sphyrna lewini, Papa Mbingusi Mapengo au Nyundo (Scalloped hammerhead) Sphyrna mokarran, Papa Mbingusi Mkubwa au Nyundo (Great hammerhead) Squalus mitsukurii, Papa Mdogo (Shortspine spurdog) Squatina africana (African angelshark) Stegostoma fasciatum, Papa Chui (Zebra or Leopard shark) Triaenodon obesus, Papa Suruanzi (Whitetip reef shark)
Rashid Anam & Edoardo Mostarda (2012) Field identification guide for the living marine resources of Kenya. FAO, Rome. Gabriella Bianchi (1985) Field guide to the commercial marine brackish-water species of Tanzania. FAO, Rome.