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Carcharhinus porosus

(Aleton)

Overview

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Family : Requiem sharks ; Found in the continental shelves, preferably over muddy bottoms , and especially in estuaries. Feeds mainly on small fishes including young hammerhead and sharpnose sharks , and shrimps. Viviparous, with 2 to 7 young in a litter . Size at birth between 31 and 40 cm. Utilized fresh for human consumption and processed for fishmeal , and liver extracted for oil .

Interesting Facts

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Common Names

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Click on the language to view common names.

Common Names in Creole, French:

Réquiem tiqueue

Common Names in Creoles and Pidgins, French:

Réquiem tiqueue

Common Names in Danish:

Sm, Småhalet haj

Common Names in Dutch:

Kleinstaarthaai

Common Names in English:

Requiem Shark, Shark, Small-tailed shark, smalltail shark, Tiburon Peninsula Limia, Tollo

Common Names in Finnish:

Sarda

Common Names in French:

Réquiem tiqueue, Requin tiqueue

Common Names in Mandarin Chinese:

小尾真鯊, 小尾真鲨

Common Names in Portuguese:

Azeiteiro, Ca, Cação, Cação-azeiteiro, Cação-do-salgado, Junteiro, Sicuri-branco, Triaqueira, Trisqueira

Common Names in Spanish:

Aleton, Cabeza dura, Cazón, Chaspat, Cuero duro, Cuero Duro O Cabeza Dura, Sarda, Tibur, Tibur?n Poroso, tiburón poroso, Tiburón aletón, Tiburón cuero duro, Tiburón poroso, Tiburón tollo, Tollo

Description

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Physical Description

Species Carcharhinus porosus

Distinctive Features: The smalltail shark has a slender fusiform body with a long pointed snout and large eyes. It has small and inconspicuous labial furrows and short gill openings. The first dorsal fin, originating over the inner margins of the pectoral fins, is large and falcate with a rounded tip . The second dorsal fin is relatively small and originates over or just behind the midbase of the anal fin. The pectoral fins are small with narrowly rounded or pointed tips. There is no interdorsal ridge on this species. The anal fin is deeply notched .

Coloration : The upper body is bluish-gray or gray, sometimes with an inconspicuous white band on the flank region. The gray coloration fades to a pale or white underside. The pectoral, dorsal, and caudal fins may have faint dusky or black markings.

Dentition: Dentition of the smalltail shark consists of 14-15 teeth in each side of both jaws . The teeth in the upper jaw are broadly triangular and strongly serrated with high cusps . The symphysial teeth number 1-2 in the upper jaw. The crown feet have coarser serrations and postlateral cusplets . The lower teeth have semierect or oblique , narrow cusps on larger bases . The number of symphysial teeth in the lower jaw ranges from 0 to 2.

Denticles : Dermal denticles of the smalltail shark overlap very little, leaving the skin somewhat exposed between them. The blades vary in size and are a bit wider than long. There are three ridges present in small individuals, increasing to five in larger sharks . The median tooth is easily the largest with very short pedicels.

Size, Age, and Growth: The maximum reported size of the smalltail shark is 4.4 feet (1.3 m ) total length. However, the average size of an adult specimen is 3-3.6 feet (0.9-1.1 m) in length with females growing to larger sizes than males. Males reach maturity at 2.5 feet (.75 m) and females at 2.8 feet (.84 m) total length.

Although data pertaining to the lifespan of the smalltail shark is lacking, individuals measuring approximately 3.3 feet (1 m) in length have been determined to be 12 years of age based on vertebrae samples .

The growth rate of the smalltail shark is 2.8 inches (7 cm) per year during the first four years of life, slowing to 1.6 inches (4 cm) per year after maturity is reached. Males are commonly 90 cm (Total Length) in length when caught/marketed, but may be as large as 150 cm (Total Length).

Habitat

Common in waters over continental shelves, the smalltail shark prefers muddy bottoms in estuarine habitats . It swims along the bottom to depths of 118 feet (36 m ).

Ecology: Common in waters over continental shelves, the Smalltail Shark prefers muddy bottoms in estuarine habitats . It swims along the bottom to depths of 36 m .

BRAZIL: The largest specimen ever caught in northern Brazil was a 128.5 cm TL female. However, the largest specimen analyzed in the literature cited here was a female measuring 120.5 cm TL and the smallest a 29.4 cm TL male (Lessa et al. 1999). The modal class in samples was 50 to 60 cm TL for both sexes. Age ranged from zero (newborns) to 12 years for individuals between 30 and 101 cm TL. Developed embryos of 28.5 cm TL were observed in the area; the average size at birth is 30 cm TL. The average fecundity is six embryos per female (Lessa et al. 1999). A resting break is suggested between successive pregnancies, implying a biennial cycle. The length- weight relationship did not differ significantly between the sexes. Diameter of ovarian follicles, presence of eggs/embryos and nidamental gland traits in female point to a major physiological change toward maturity at about 70.0 cm. Vitellogenesis was first observed at 63.0 cm, and the smallest of the six pregnant females was 70.0 cm; there was a significant relationship between the number of embryos and female size (Lessa et al. 1999) The size at 50% of maturity is 71 cm TL (males) and 70 cm TL (females) (Lessa et al.1999). Age and growth were estimated from vertebral analysis for individuals ranging from zero to twelve years. Von Bertalanffy growth parameters were: L? = 136.4 cm TL, K= 0.077 year-1 and t0 = -3.27 year.

The Smalltail Shark is an opportunistic predator , feeding primarily on small fishes including sea catfish, croakers, jacks and grunts , it also consumes aquatic invertebrates including crabs and shrimps. Adults may prey upon elasmobranchs, whereas juveniles show a wider food spectrum. Ontogenetic differences in diet were observed for both males and females. There is evidence of size selection of prey related to predator size (Lessa and Almeida 1997).

Life history parameters
Age at maturity: Male & Female: 6 years (Lessa and Santana 1998).
Size at maturity (total length): Female: 70 cm (Lessa and Santana 1988), 72 to 78 cm (Compagno et al. 2005); Male: 71 cm (Lessa and Santana 1998), 84 cm (Compagno et al. 2005)
Longevity : 12 years (Lessa and Santana 1998).
Maximum size (total length): 128.5 cm (Maranhão - Lessa et al. 1999); 134 cm (São Paulo - Sadowsky 1967); et al. 2005).
Size at birth: 30 cm (observed) and 31.1 cm (back-calculated) (Lessa and Santana 1998); 31-40 cm (Compagno et al. 2005).
Average reproductive age: 6 years (Lessa and Santana 1998).
Gestation time: ~12 months (Lessa et al. 1999).
Reproductive periodicity: Biannual cycle (Lessa et al. 1999).
Average annual fecundity or litter size : Average 6 embryos; maximum 9 (Lessa et al. 1999, Stride et al. 1992).
Annual rate of population increase: Unknown.
Natural mortality : 0.20 (Hoening´s Model ); 0.23 (Pauly´s Model) (Santana da Silva 2001)..[1].

List of Habitats:

Biology

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Diet

The smalltail shark is an opportunistic predator , feeding primarily on small fishes including sea catfish, croakers, jacks , and grunts . The smalltail shark also eats aquatic invertebrates including crabs and shrimps. Adult smalltail sharks feed on other elasmobranchs such as young hammerhead (Sphyrna spp. ) and sharpnose (Rhizoprionodon spp.) sharks.

Reproduction

The mode of reproduction for the smalltail shark is viviparity with a yolksac. The gestation period is approximately 10 months or more. Birth takes place during the spring and summer months in the waters off Brazil. There are 2-9 pups per litter , depending on the size of the female. Each pup measures 12.2-15.7 inches (31-40 cm) in length at time of birth.

Behavior

Predators : Large sharks are potential predators of the smalltail shark , especially of juvenile individuals.

Taxonomy

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Synonyms

Carcharhinus cerdale Gilbert • Carcharhinus porosus • Carcharhinus porosus (Ranzani, 1840) • Carcharias henlei Müller & Henle • Carcharias porosus Ranzani • Carcharias porosus Ranzani, 1839

Notes

Name Status: Accepted Name .

Last scrutiny: Data last modified by FishBase 28-Oct-2000

Similar Species

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Members of the genus Carcharhinus

ZipcodeZoo has pages for 36 species and subspecies in this genus:

C. acronotus (Blacknose Shark) · C. ahenea (Shortnose Blacktail Shark) · C. albimarginatus (Silvertip Shark) · C. altimus (Knopp´s Shark) · C. amblyrhynchoides (Graceful Shark) · C. amblyrhynchos (Shortnose Blacktail Shark) · C. amboinensis (Ambon Sharpnose Puffer) · C. azureus (Large Blacktip Shark) · C. borneensis (Borneo Mullet) · C. brachyurus (Black-Tipped Whaler) · C. brevipinna (Blacktipped Shark) · C. cautus (Sharks Bay Whaler Shark) · C. dussumieri (Whitecheek Shark) · C. falciformis (Sickle-Shaped Shark) · C. fitzroyensis (Creek Whaler Shark) · C. galapagensis (Galapagos Shark) · C. hemiodon (Pondicherry Shark) · C. isodon (Fintooth Shark) · C. leiodon (Smoothtooth Blacktip Shark) · C. leucas (Bull Shark) · C. limbatus (Blacktip Shark) · C. longimanus (Brown Milbert's Sand Bar Shark) · C. macloti (Hardnose Shark) · C. melanopterus (Black Fin Reef Shark) · C. obscurus (Dusky Shark) · C. perezi (Caribbean Reef Shark) · C. perezii (Caribbean Reef Shark) · C. plumbeus (Northern Whaler Shark) · C. porosus (Tiburon Peninsula Limia) · C. sealei (Black-Spot Shark) · C. signatus (Night Shark) · C. sorrah (West Australian Whaler Shark) · C. springeri (Reef Shark) · C. tilstoni (Australian Blacktip Shark) · C. velox (Whitenose Shark) · C. wheeleri (Blacktail Reef Shark)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal March 01, 2008:

Identifiers

Footnotes

  1. Lessa, R., Almeida, Z., Santana, F.M., Siu, S. & Perez, M. 2006. Carcharhinus porosus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 31 January 2012. [back]
Last Revised: 7/15/2012