The Pencil Shark (Hypogaleus hyugaensis) is a medium-sized (to 150 cm total length) shark with a disjunct distribution across the Indo-West Pacific (eastern Africa, southern Australia, Taiwan, Japan) in waters from 40 to 480 m depth. There are some life history data available, but age and growth information is lacking. Its patchy distribution and naturally low abundance throughout its range, and presence in countries with significant fisheries within its depth range (e.g., Taiwan, Japan) increase the potential for fishing pressure to cause population reduction. However, its relatively pelagic lifestyle and outer continental shelf distribution may offer refuge from some fisheries. Overall, there is a lack of information on catches and status from outside of Australia, but the low level and stability of catches off Western Australia (where it is a small component of a demersal gillnet fishery) suggests that it is sustainably fished there. However, these data have not been updated in over 20 years, increasing uncertainty about their current status. As such, given the lack of data from much of its geographic range, and the long period since data were available from Western Australia, it is unknown if the fishing is causing a population reduction and there is currently inadequate information to assess the species beyond Data Deficient.

The Pencil Shark has a disjunct distribution in the Indo-West Pacific where it has been recorded in the Northwest Pacific Ocean from Japan (Miyosi 1939) and Taiwan (Chen 1963, Ebert 2013), southern Australia (Western Australia, South Australia, Victoria, Tasmania, New South Wales, Queensland; Heald 1987, Last and Stevens 2009), and in the Western Indian Ocean from South Africa (KwaZulu-Natal), Mozambique (Pierce et al. 2008), Tanzania (Zanzibar) and Kenya (Smith 1957, Bass et al. 1975, Bennett et al. 2023). Records of this species from the Persian/Arabian Gulf are now known to be the Slender Weasel Shark Paragaleus randalli (Jabado et al. 2015). Since the previous assessment (Simpfendorfer and Compagno 2016), the distribution map has been refined to map this species to its known bathymetric range.

There are limited data available on the status of the Pencil Shark population. Generally it occurs in low abundance, and is considered to be naturally rare (Ebert et al. 2021). In Australia, catch rate data from the southwest indicate that the population was stable until 1999 (Simpfendorfer et al. 2002). The lack of catch rate data since 1999 make it difficult to evaluate the contemporary status of the species. However, catches of Pencil Shark in the southwest fishery (Western Australian Temperate Demersal Gillnet and Demersal Longline Fishery) are typically less than 5 t annually, and have declined over time as fishing effort and shark catches in the fishery have declined (Braccini et al. 2021). It is rarely encountered off southeast Australia (T. Walker, pers. comm., 2000; Last and Stevens 2009). There are no population trend data from other regions. There is no information available on the population structure and it is unknown whether there are discrete subpopulations in the Western Indian Ocean, off Australia, and in the Northwest Pacific Ocean off Japan and Taiwan.

A recent Australian national Red List assessment for the species assessed it as Least Concern on the basis of catches being very low and that when it had been monitored more closely the population was stable (Kyne et al. 2021). The lack of information on status from other subpopulations that occur in regions with relatively intensive fisheries, including in the depth range in which it occurs, means that there is some concern that declines have occurred. Although, its semi-pelagic lifestyle that results in relatively low catchability in demersal fisheries may provide it significant refuge from fishing pressure. However, the lack of survey data from these regions limits the ability to make conclusions about the status of the population. Given the limited catch data from much of its geographic range, and the long period (>20 years) since catch data were compiled for the population in southwestern Australia, it is unknown if fishing is causing a population reduction, and the species is assessed as Data Deficient.

The Pencil Shark occurs over the continental shelf mainly at depths of 40–230 m, and rarely on the upper slope to a depth of 480 m (Last and Stevens 2009). Its diet (squid and pelagic teleosts) suggest that it is more bentho-pelagic than truly demersal (and therefore, may not be well sampled in research surveys and it may also be less susceptible to capture in demersal fishing gears). It is reported to reach 150 cm total length (TL) (Last and Stevens 2009), although Bass et al. (1975) reported specimens up to 127 cm TL from the eastern African coast, reports from Asia are all for specimens less than 90 cm TL, and the maximum size of this species recorded from extensive catch sampling in the Western Australia shark fishery is 117 cm TL (Simpfendorfer et al. 2002).

The Pencil Shark is placental viviparous and has been reported to have a seasonal reproductive cycle (Bass et al. 1975, Stevens 1990). Results from biological monitoring of the catch from the Western Australia commercial shark fishery have provided a clearer picture of the reproductive biology of the Pencil Shark (Simpfendorfer et al. 2002). Males mature at approximately 98 cm TL and females at approximately 102 cm TL. Ovulation occurs in March and April, while the largest embryos are observed from December to February. The gestation period is probably around 10–11 months. Litter sizes range from 3–15, with a mean of 10. On the basis of full-term embryos, the size at birth is approximately 30 cm TL, a value similar to that of 33–35 cm TL suggested by Bass et al. (1975) from full term embryos observed in southern Africa. Pregnant females do not produce yolky ova, suggesting that breeding occurs every second year (Simpfendorfer et al. 2002).

There are no known targeted fisheries for the Pencil Shark, but it is caught as bycatch in a number of fisheries throughout its range, including Australia, South Africa and Japan. It is taken in demersal gillnets set by commercial shark fishers in Western Australia (Simpfendorfer and Donohue 1998). Catch and effort data are available in this fishery from 1989–1999 and show that although catches have decreased over this period the catch rates have remained stable, suggesting there has been little impact on the population (Simpfendorfer et al. 2002). Little is known of this species in Taiwan and Japan, but both countries have large inshore demersal fisheries that may catch this species. It is also caught in trawl fisheries off the east coast of southern and eastern Africa, including the shrimp trawl fishery off KwaZulu-Natal (Bass et al. 1975). Little data are available for this fishery, but intensive fishing may have caused some previous decline in the stock. However, these trawl fisheries have decreased in effort since 2008 and catches are now likely minor as it was not reported in South African fisheries catches from 2010–2012 (da Silva et al. 2015, S. Fennessy pers. comm. 2018). Currently, there are no data available on the occurrence of this species in other commercial fisheries. However, it is probable that it is caught in demersal fisheries (e.g., trawl, gillnet, and longline) on the outer continental shelf where it occurs.

In southwestern Australia, the Pencil Shark is taken as a byproduct species in a commercial gillnet fishery (Western Australian Temperate Demersal Gillnet and Demersal Longline Fishery). Elsewhere, it is occasionally taken in fisheries, but is not known to be targeted. Similar to other shark species captured in eastern Africa, its meat is likely consumed by coastal communities.

There are currently no specific management or conservation measures in place for this species. However, the directed shark fishery in Western Australia that catches this species is a limited entry fishery with effort controls and gear restrictions (Simpfendorfer and Donohue 1998). There are a number of no-take marine reserves within the species' range, that might provide some refuge from fishing, but the level of refuge is unknown. Further research is needed on population size and trends, and life history, and catch rates should be monitored.