flatfish

An Octopuses garden By Darren Stevens First published in Aquarium World August 2013 We have about 40 octopus species in our waters, including representatives of all twelve octopus families. Octopus are among the most intelligent of all invertebrates (animals without a backbone) and many shallow water species are masters at camouflage being able to change their colour and texture to suit their surroundings using chromatophores (pigment filled sacs under individual nervous control). This is despite the fact that they are colour blind. Most octopus species live on or close to the bottom, however there are several pelagic (live in the water column over deep water) species, many of which are found in New Zealand waters. Pelagic octopuses tend to have a gelatinous body and are often small. An exception is the rare pelagic species Haliphron atlanticus, which may be the largest of all Octopuses. The single incomplete specimen collected in New Zealand waters is the largest specimen known and is estimated to have weighed 75 kg’s and to have been about 4 metres long. The other contender for the world’s largest octopus is the giant Pacific octopus (Enteroctopus dofleini) which reaches at least 71kg. In stark contrast, the world’s smallest known octopus is the tiny star-sucker pygmy octopus (Octopus wolfi) which grows to only 1.5 cm in length and weighs less than 1 gram. Octopus are dived into two main groups: the incirrate octopus (Suborder Incirrata) which resemble our large common inshore octopus, and the cirrate or ‘dumbo’ octopus (Suborder Cirrata) which are much more bizarre. In this article we will look at a selection of the octopus species we have in New Zealand waters. Incirrate octopus Our large common inshore octopus, Pinnoctopus cordiformis (also sometimes called Octopus maorum) is a typical incirrate octopus with a sac-like, often lumpy body, two eyes, and four pairs of arms. There are a number of New Zealand cirrates with this general body plan. Here’s a selection. Common octopus Pinnoctopus cordiformis (Photo credit: Darren Stevens, NIWA) This large long-armed light to dark brown or red octopus needs little introduction. The common octopus grows to about 1.5 metres in total length (end of head-like body to tip of longest leg) and about 10 kg’s. Its inquisitive nature and coastal distribution mean it is frequently seen by divers and is a common display animal in large public aquariums. As juveniles common octopus are often found in tidal rock pools but as they mature they move out to deeper water. It is found around North, South, Stewart, and Chatham Islands, and Southern Australia from the intertidal zone to about 300 metres depth. Yellow octopus Enteroctopus zealandicus (Photo credit: Darren Stevens, NIWA) The yellow octopus (Enteroctopus zealandicus) is striking large (to 1.4 metres total length) yellow to orange smooth-bodied octopus. It is found on the East Coast of the South Island from the Chatham Rise (an undersea ridge between the South Island and the Chatham Islands) to the sub-Antarctic Auckland and Antipodes Islands. It is generally found in deep water (300–522 metres), but in southern waters juveniles are found in the intertidal zone. The yellow Octopus is closely related to the giant Pacific octopus (E. dofleini), one of the world’s largest octopus species. The real Octopus Along with the large common and yellow octopuses there are also about 7 true Octopus species in New Zealand waters. Most New Zealand Octopus species are small ranging in size from about 13 to 40 cm in total length. Some of the smaller species would make great subjects for a saltwater aquarium and can be found in shallow water. Octopus huttoni grows to about 24 cm in total length and is found around New Zealand from the intertidal zone to 386 metres depth. Octopus kaharoa (pictured) grows to about 40 cm in length and is found from 7–540 metres depth on the east coast of the North and South Islands from the Poor Knights Islands to Kaikoura. Octopus gibbsi grows a little larger reaching 68 cm in length and is found on the northeastern coast of the North Island from the intertidal zone to about 40 metres depth. Octopus kaharoa (Photo credit: Darren Stevens, NIWA) Along with these more ‘typical’ looking octopus there are few deeper water incirrate octopus that are a little more unusual. Here are a couple. Deepwater warty octopus Graneledone taniwha (Photo credit: Darren Stevens, NIWA) These unusual stocky octopus have clusters of cartilage-like warts on the head, mantle, and arms giving rise to their common name of deepwater warty octopus. There are 2 species of deepwater warty octopus (Graneledone species) in New Zealand waters found in 450 to 1500 metres depth. Thaumeledone zeissThaumeledone zeiss (Photo credit: Darren Stevens, NIWA) This endearing little octopus (to 12 cm total length) with short arms and big eyes doesn’t have a common name and is only known from a handful of specimens captured in very deep water (1000–1400 metres) off the east coast of the South Island. A related species is found in even deeper water. Cirrate octopus These spectacular deep-sea octopus are anything but typical and come in a variety of bizarre forms. All species have a semi-gelatinous body, a pair of fleshy ‘fins’ on the mantle (head-like body), strong webbing between the arms, and a row of cirri (minute fleshy finger-like projections) along each side of the suckers on a leg. Most species are an orange/red/purple colour and all species lack chromatophores, so they are incapable of changing colour. Most species live close to or on the sea floor and generally feed on small, slow moving prey, such as small crustaceans (amphipods - like the sand-hoppers found at the beach, and shrimps) and polychaetes (sea worms). Unlike the more typical-looking inshore octopus which can move rapidly by jet propulsion, dumbos generally move at a sedate, energy efficient pace; crawling along the bottom, drifting with the current, swimming using their large fins, or by pumping their webbed arms. There are about 9 species of dumbo octopus in New Zealand waters. Here are a couple of types: Umbrella Octopus Opisthoteuthis robsoni (Photo credit: Darren Stevens, NIWA) The bizzare gelatinous umbrella octopus (Opisthoteuthis spp.) look a little like a flattened jellyfish. However as with all cirrate octopus they have a pair of ear-like fins and eight strongly webbed arms, each with a single row of suckers. There are 3 species of umbrella octopus in New Zealand waters, which grow up to about 30 cm in length and depending on the species they can be found from 360 to 1700 metres depth. Dumbo octopus Cirroctopus spp. from the Ross Sea, Antarctica (Photo credit: Peter Marriott, NIWA) With its large muscular fins resembling ears and plain coloration it’s not hard to see why these octopus are sometimes called dumbo octopus. The New Zealand species Cirroctopus hochbergi is found off the east coast of the North Island in 700 to 1350 metres depths. The remaining 3 species are found in Antarctic waters (including the one pictured above). So there we have it. An introduction to New Zealand’s cephalopods. So next time when see a common octopus or a broad squid during a dive in the sea, or dive into a feed of squid rings at your local takeaway just think of the many other cephalopods that make up New Zealand’s marine fauna. There are lots of other cool invertebrate critters on the NIWA Invertebrate Collection Facebook page (www.facebook.com/NIWAInvertebrateCollection). References Wikipedia (http://en.wikipedia.org) Tolweb (http://tolweb.org) Cook, S. de C. (ed.) (2010). New Coastal Marine Invertebrates 1. Canterbury University Press. 640 pp. O'Shea, S. 1999. The Marine Fauna of New Zealand: Octopoda (Mollusca: Cephalopoda). NIWA Biodiversity Memoir 112: 280pp. © This item may not be reproduced without written permission

Butterflies and flatheads Author: Darren Stevens First published in Aquarium World November 2011 In the previous articles, we have covered the main groups of plecos, and a few examples of each. However there are about 700 pleco species so it’s not surprising that we have left a few out. Many of these species are relatively plain and/or rare, so are unlikely to be popular in the hobby, but there are a few other beauties that have been imported in the past. Dekeyseria The genus Dekeseria contains six scientifically described species and at least one awaiting a scientific name. All of these plecos have a broad flattened profile. They often inhabit black water rivers (i.e. those stained by tannins and humic acid from decaying vegetation) so not surprisingly, they prefer soft acidic water. Two of these species have been imported into New Zealand on several occasions. Butterfly plecos (Dekeyseria brachyura, L168 and Dekeyseria sp. L052) The name butterfly or flounder pleco is used for two very similar species. The butterfly pleco, Dekeyseria brachyura, L168, is a stunning black fish with broad white to yellowish bands and it originates from the Rio Negro in Brazil. The Atabapo butterfly pleco, Dekeyseria species L052 originates from blackwater tributaries of the upper Rio Orinoco. It is similar in appearance to Dekeyseria brachyura but the bands are duller and have more of a network pattern. Both of these species reach about 14 cm and under optimal conditions they are strikingly coloured; however, they can change their colour to suit their mood or surroundings and, when they adopt fright colouration, they are much duller. In the wild both species are unspecialised aufwuchs (essentially algal biofilm) feeders, but in aquaria they do well on a varied diet. They are suited to community tanks with a pH range between 5.6–7.0 and a temperature range of 25–29ºC. They can be kept in more alkaline aquaria but they are less likely to breed and be attractively patterned. Both types of butterfly pleco have been bred successfully in New Zealand. Parancistrus The genus Parancistrus contains 2 scientifically described species, and a couple of other varieties awaiting a scientific name. Parancistrus are broad stocky, strongly flattened plecos with large robust scutes, and a very large gill opening. The dorsal fin is connected to the adipose fin by a membrane. They prefer fast moving water and require high levels of dissolved oxygen. Parancistrus should be fed on a varied diet, including live and frozen foods. They are generally peaceful and only slightly territorial. One species, Parancistrus aff. auranticus (LDA046), has occasionally been imported into New Zealand. Chubby plecos (Parancistrus aurantiacus and P. aff. aurantiacus, LDA046) The name chubby pleco is often applied to two very similar plecos: Parancistrus aurantiacus and Parancistrus aff. aurantiacus (LDA046). The real chubby pleco, P. aurantiacus, is a large (to about 30 cm TL) black pleco from the Rio Araguaia (which flows into the Rio Tocantins) in north-eastern Brazil. Bizarrely, some individuals can change colour to golden yellow or a pied or marbled black and yellow pattern. The golden yellow individuals often command very high prices overseas, but they rarely retain their colour long term. Parancistrus aff. aurantiacus, LDA046, is a smaller (to about 15 cm) dark grey pleco from the Rio Tocantins and it is covered with a network of light lines and/or spots. It also sometimes changes to a yellow colour. Both chubby plecos are suited to larger tanks with a pH range of 5.5–7.5 and temperatures between 25–29ºC and have been bred in captivity a few times. Pseudancistrus The genus Pseudancistrus contains 18 scientifically described species, and several other species awaiting a scientific name. The name Pseudancistrus comes from the Greek word ‘pseudes’ meaning false, and in this case it refers to the Pseudancistrus species being similar to, but not the same as Ancistrus.Pseudancistrus are generally found among rocks in rapids in northern South America where they feed on aufwuchs, and as such they should be fed on a mainly vegetarian diet with only very small quantities of meaty foods. Males can be very territorial. One species, Pseudancistrus asurini (L67) has occasionally been imported into New Zealand. ‘Flathead gold nugget’ (Pseudancistrus asurini, L67) Pseudancistrus asurini (L67) is a lovely medium sized (to about 20 cm standard length, SL) dark brown pleco with fine gold spots. In New Zealand they were sold as ‘flathead’ gold nuggets although this is not a recognised common name. They originate from the Rio Xingu in Brazil where they occur alongside other very similar patterned plecos such as the gold nuggets (Baryancistrus xanthellus, Baryancistrusspecies L081) and Hopliancistrus species L017. It is suited to larger tanks with a pH range of 5–7 and temperatures between 25–30ºC. This species has not been bred in captivity. Spectracanthicus/Oligancistrus The genus Spectracanthicus contains five scientifically described species and a handful of species awaiting a scientific name. The Genus Spectracanthicus is very similar to the Genus Oligancistrus and recent scientific publications, including a 2014 revision, only regard Spectracanthicus as valid (i.e. allOligancistrus species should be placed in Spectracanthicus). They are omnivores and should be given a varied diet. They are restricted to the tributaries of the lower Amazon in north-eastern Brazil. The peppermint pleco (L030), a form of Spectracanthicus punctatissimus, has occasionally been imported into New Zealand. Peppermint pleco (Spectracanthicus (formerly Oligancistrus)punctatissimus L016, L030, L353) The peppermint pleco is a lovely little (to 10 cm standard length) black pleco with small widely spaced off-white spots. It originates from the lower course of the Rio Xingu and is suited to aquaria with a pH range of 5.5–7.5 and temperatures between 26–30ºC. This species has been bred in captivity overseas. Leporacanthicus The genus Leporacanthicus contains four described species and a few species awaiting a scientific name. All have about four large long teeth on their upper jaw giving rise to their common name of vampire pleco. It is thought these long teeth are used to prise prey from crevices in wood and between rocks. All species are largely carnivorous and do well on a high protein diet (e.g., shrimp pellets, carnivore tablets, mosquito larvae, blood worms, shrimps, etc.). At least two species of Leporacanthicus have been imported into New Zealand. The vampire plecos (Leporacanthicus galaxias and L. heterodon) The vampire or galaxy pleco (Leporacanthicus galaxias, L007, L029) is a striking black pleco with white to yellowish spots and originates from the Rio Tocantins in north-eastern Brazil. It is relatively large (up to 30 cm SL) and is suited to larger tanks with a pH range of 5.5–7.5 and temperatures between 25–29ºC. The golden vampire pleco (Leporacanthicus heterodon) is a smaller (to 15–20 cm SL) tan pleco with black spots and originates from the lower and middle Rio Xingu in Brazil. It is suited to larger tanks with a pH range of 5–7 and temperatures between 26–30ºC. Both species of Leporacanthicus have been bred several times overseas. There are other plecos that occasionally surface in New Zealand. However these articles have covered the main plecos that you are likely to see here. Thanks to Jennifer Hamlin for her comments and improvements on an earlier version of this article. References: Planet catfish (www.planetcatfish.com) Wikipedia (en.wikipedia.org) Jonathan Armbrusters Loricariidae website (http://www.auburn.edu/ academic/science_math/res_area/loricariid/fish_key/lorhome/ index.html) Seidel, I. (2008). Back to nature guide to L-Catfishes. Fohrman Aquaristik AB, Sweden. 208 p. Chamon, C.C. and Rapp Py-Daniel, L.H. (2014). Taxonomic revision of Spectracanthicus Nijssen & Isbrücker (Loricariidae: Hypostominae: Ancistrini), with description of three new species. Neotropical Ichthyology 12: 1–25. Rapp Py-Daniel, L.H. (1989) Redescription of Parancistrus aurantiacus (Castelnau, 1855) and preliminary establishment of two new genera: Baryancistrus and Oligancistrus (Siluriformes, Loricariidae). Cymbium 13: 235–246. Silva, G.S.C., Roxo, F.F. and Oliveira, C. (2015). Two new species of Pseudancistrus (Siluriformes, Loricariidae) from the Amazon basin, northern Brazil. ZooKeys 482: 21–34. Deuschle, F. (2018). The broadheaded Loricariids of the genus Parancistrus Bleeker, 1862. BSSW Report 30: 30–41. © This item may not be reproduced without written permission